Posts Tagged ‘paper’

Critical Review of Tesseract

Tuesday, May 4th, 2010

For CA640 we were supposed to pick a paper from International Conference of Software Engineering 2009 (ICSE 2009) and critically review it.

I chose to review Tesseract: Interactive Visual Exploration of Socio-Technical Relationships in Software Development.

You can find the review in PDF here. Its abstract reads:

This critical review of a paper, which presents Tesseract and was handed in for the ICSE 2009, focusses on
strength and weaknesses of the idea behind Tesseract: Visualising and exploring freely available and loosly coupled fragments (mailing lists, bug tracker or commits) of Free Software development.
Tesseract is thus a powerful data miner as well as a GUI to browse the obtained data.

This critique evaluates the usefulness of Tesseract by questioning the fundamental motivation it was built on, the data which it analyses and its general applicability.

Existing gaps in the original research are filled by conducting interviews with relevant developers as well as providing information about the internal structure of a Free Software project.

Tesseract is a program that builds and visualises a social network based on freely available data from a software project such as mailing lists, bug tracker or commits to a software repository. This network can be interactively explored with the Tesseract tool. This tool shows how communication among developers relates to changes in the actual code. The authors used a project under the GNOME umbrella named Rhythmbox to show their data mining and the program in operation. GNOME is a Free/Libre Software Desktop used as default by many Linux distributions including the most popular ones, i.e. Ubuntu and Fedora. To assess Tesseracts usability and usefulness, the authors interviewed people not related to Rhythmbox asking whether Tesseract was usable and provided useful information.

The paper was particularly interesting for me because the authors analysed data from the GNOME project. As I am a member of that development community, I wanted to see how their approach can or cannot increase the quality of the project. Another focus was to help their attempt to improve GNOME by highlighting where they may have gaps in their knowledge of its internals.

During this critique, I will show that some assumptions were made that do not hold for Free/Libre and Open Source Software (FLOSS) in general and for GNOME in particular either because the authors simply did not have the internal knowledge or did not research carefully enough. Also I will show that the used data is not necessarily meaningful and I will attempt to complement the lacking data by presenting the results of interviews I conducted with actual GNOME developers. This will show how to further improve Tesseract by identifying new usage scenarios. Lastly, this text will question the general usefulness of Tesseract for the majority of Free Software projects.

MSN Shutdown in 2003

Monday, March 8th, 2010

During CA640 I was made to write an ethical review which I was supposed to hand in using a dodgy webservice. Since it got 90% people mugged me to make it available ;-) Of course, I don’t have a problem with that, so people now have a reference or know what to expect when they enter the course.

You can find the PDF here and its abstract reads:

At the end 2003 Microsoft closed the public chat-rooms of its Internet service called MSN.
MSN was pushed by Children’s Charities because they feared an abuse of these chat-rooms.
In some countries, however, the service was still available but subject to a charge.
This review raises ethical questions about Microsoft’s and the Children’s Charities’ behaviour because making the people pay with the excuse of protecting children is considered ethically questionable.
Also the Children’s Charities pushed for closure of a heavily used service although there is absolutely no evidence that children would be safer after closing down a chat-room.

If you are not interested in the non-technical details you might be interested to know that I use a Mercurial Hook on the server side to automatically compile the LaTeX sources one I push changes to the server:

$ cat .hg/hgrc
[hooks]
changegroup.compile = export FILE=paper && hg up -C && pdflatex --interaction=batchmode $FILE && bibtex $FILE && pdflatex --interaction=batchmode $FILE && pdflatex --interaction=batchmode $FILE

And then I just symlink that resulting PDF file to my public_html directory.

Digital Divide

Sunday, February 14th, 2010

Als Student kommt es hin und wieder vor, dass ich eine Hausarbeit schreiben muss. Da ich fest davon ueberzeugt, dass Uni, Wissenschaft und Wissen so frei wie moeglich sein sollten, und jedermensch auch noch durch Zahlung von Steuern potentiell das Studieren finanziert, denke ich, hat jedermensch das Recht mindestens zu sehen was ich so eigentlich den lieben langen Tag so mache.

Internet sei dank ist es heutzutage eher einfach, Dinge zu publizieren und Wissen fortzutragen. Deswegen gibt es hier nun eine Hausarbeit, die ich im letzten Semester in Gender Studies geschrieben habe.

Alien Toilet Sign

Alien Toilet Sign

Das Paper traegt den Namen “Weiblicher Zugang zu Technik und feministische Politiken” und das Abstract liesst sich wiefolgt:

Die Gründe, die zum Digital Divide, der digitalen Kluft, führen, sind vielfältig und Geschlecht ist einer davon.
Auch weibliche Gruppierungen haben das Ziel, den Anteil weiblicher Teilnehmer im Digitalen zu erhöhen.
Die Arbeit analysiert, wie dieses Ziel erreicht werden soll, warum das nicht gelingt und wie es eventuell doch erreicht werden kann.

Das PDF gibt es hier und ist als “Namensnennung-Keine kommerzielle Nutzung-Weitergabe unter gleichen Bedingungen 3.0 Deutschland” fuer jedermensch lizensiert. Das heisst aber nicht, dass ich es auf Anfrage anders lizensieren kann.

Die Arbeit liesst sich an einigen Stellen etwas ruckelig, was der Entstehungsgeschichte geschuldet ist. Im Prinzip sind aus 2.5 Arbeiten eine geworden. Ich hoffe, es ist dennoch nicht so schlimm.

Sollte das PDF inhaltlich nicht so spannend sein, lohnt es sich doch auf die technischen Details zu achten. So weiss das PDF, wie dessen Inhalt lizensiert ist. Dazu benutzt es XMP streams, die in das PDF eingebetted wurden. Die sind mit dem Paket hyperxmp ueber LaTeX in das PDF gekommen. Offiziell wird noch xmpincl empfohlen, aber das ist wirklich fies zu benutzen, weil mensch den XMP stream selbst erstellen muss.

\usepackage{hyperxmp}         % To be have an XMP Data Stream f.e. to include the license
[...]
\hypersetup{
        pdftitle={Weiblicher Zugang zu Technik und feministische Politiken},
        pdfauthor={Tobias Mueller},
        [...]
        pdfcopyright={This work is licensed to the public under the Creative Commons Attribution-Non-Commercial-Share Alike 3.0 Germany License.},
        pdflicenseurl={http://creativecommons.org/licenses/by-nc-sa/3.0/de/}
}

Mein Evince 2.29.1 (mit JHBuild gebaut) zeigt die Lizenzinformation froehlich an, Okular 0.9.2 nicht. Wie es sonst moeglich ist, in PDF eingebettete XMP Daten anzusehen, weiss ich nicht. Es waere fuer eine automatisierte Verarbeitung sicherlich interessant.

Vielen Dank and Chillum und Sourci, die mir beratend und patchend zur Seite standen und denen der Text wahrscheinlich zu den Ohren wieder herauskommt ;-)

Fuer eine inhaltliche Diskussion ist die Kommentarfunktion wohl eher schlecht geeignet aber in Ermangelung an Alternativen steht sie dazu zur Verfuegung. Ich mag die Loesung, die das Djangobook benutzt. Am Rand von jedem Absatz gibt es eine Kommentarfunktion die sehr gut funktioniert.

Adding Linux Syscall

Thursday, January 7th, 2010

In a course (CA644) we were asked to add a new syscall to the Linux kernel.Linux Oxi Power!

As I believe that knowledge should be as free and as accessible as possible, I thought I have to at least publish our results. Another (though minor) reason is that the society -to some extend- pays for me doing science so I believe that the society deserves to at least see the results.

The need to actually publish that is not very big since a lot of information on how to do that exists already. However, that is mostly outdated. A good article is from macboy but it misses to mention a minor fact: The syscall() function is variadic so that it takes as many arguments as you give it.

So the abstract of the paper, that I’ve written together with Nosmo, reads:

This paper shows how to build a recent Linux kernel from scratch, how to add a new system call to it and how to implement new functionality easily.
The chosen functionality is to retrieve the stack protecting canary so that mitigation of buffer overflow attacks can be circumvented.

And you can download the PDF here.

If it’s not interesting for you content wise, it might be interesting from a technical point of view: The PDF has files attached, so that you don’t need to do the boring stuff yourself but rather save working files and modify them. That is achieved using the embedfile package.

\usepackage{embedfile}        % Provides \embedfile[filename=foo, desc={bar}]{file}
[...]
\embedfile[filespec=writetest.c, mimetype=text/x-c,desc={Program which uses the new systemcall}]{../code/userland/writetest.c}%

If your PDF client doesn’t allow you save the files (Evince does :) ), you might want to use pdftk $PDF unpack_files in some empty directory.