- Personal website of Tess Sluijter

Unimportant background
  RSS feed

About me

Blog archives























> Weblog

> Sysadmin articles

> Maths teaching

Overview of dutch kendo dojo

2013-02-28 07:20:00

Yesterday I spent a few hours gathering information on all dutch kendo dojo. The NKR only has a list of city+dojo name on their website, which isn't terrifically navigable. I took the list, gathered all the website information and then gathered all dojo locations. I then spent an hour putting them all into a Google Maps project. The result: a map of all dutch kendo dojo.



Also in dutch, so dutch kendoka can find it:

Gisteren heb ik een paar uurtjes besteed aan het verzamelen van informatie over Nederlandse kendo dojo. De NKR heeft een lijst met steden en dojo namen op hun site staan, maar heel erg handig werkt die niet. Ik heb van alle dojo's op de lijst een overzicht gemaakt van hun website, plus het adres van hun trainingslocaties. Daarna kostte het me een uur om ze allemaal in een Google Maps project te zetten. Het resultaat: een overzicht van alle Nederlandse kendo dojo, op de kaart. tags: , , ,

View or add comments (curr. 0)

Airport Extreme custom DNS setup issues

2012-05-07 17:55:00

Airport DNS setup

Tonight, it seems that UPC are having DNS issues. I was startled that we even noticed it, because I thought we were using OpenDNS. Not so apparently. When I went to change the configuration of our Airport Extreme I found the DNS IP boxes to be greyed out. WTF?

Turns out that, in the new Airport Utility one needs to do the following:

And presto! It works. No idea why the DNS boxes work that way, but they do. Oh well. At least our DNS problems are over :p tags: , , ,

View or add comments (curr. 0)

Open Coffee networking event in Almere

2009-05-19 21:44:00

The Open Coffee Almere logo.

Taking a page out of the good book on Open Coffee networking events, I've decided to start one for Almere. Following the example of the original Open Coffee event, we'll gather every month (same Bat-time, same Bat-channel!) to meet new people over a cup of hot Java.

To get things going I've opened the Open Coffee Almere group at With a bit of luck we'll get a few dozen members soon.

To make the group stand out a little bit I've worked with InkScape for a few hours. By combining the Almere coat of arms with the common logo for most Dutch OC groups I think I've managed to create something unique. Besides, I didn't feel like re-using the same low-res image all the other groups use ;) By making the logo a vector image I've guaranteed that we can resize it to -any- size without loss of quality.


I've set up a simple Wordpress site at to act as a face to the masses. tags: , , ,

View or add comments (curr. 1)

No honor among peers: plagiarism is uncool

2008-11-19 20:57:00

T-Rex bullied someone into making his homework!

Well, this is certainly ironic... Not half a year ago my profs at college sang praise of the work I was doing and how helpful it was to publish my notes, calculations and papers on the web. This took a turn today when I received an e-mail from my mentor, asking me to remove all of my work from the web.

Apparently there is no honor among peers and there's a bunch of students that decided to be assholes and completely rip off my work. Of course it was never my intention to help people commit fraud at college. I have faith in my peers and counted on fellow students to have the balls to do their own work.

Publishing my schoolwork was always meant to be an inspiration for fellow students, possibly helping them along in their own pursuits. It'd be great if a glance or two at my work had helped them over that little bump they'd run into. I explicitly mention on my site that people shouldn't be dicks and that my work is not meant to be turned in as their own. I warn the readers that any repercussions following plagiarism of my work are their own responsibility and that I won't be held accountable for their assholish behaviour.

Anyway... It's dilemma time! I dislike the thought of hampering my old profs in their daily work. They made me feel at home at HU and they taught me a lot. On the other hand, I believe that removing my work from the web will only amount to fighting symptoms. Students will always share papers among themselves, it's just that mine are more visible. Besides, it's a very real possibility that at least a dozen students have already downloaded every single file I put up on the web, so it's impossible to stamp out any copying from my work.

I explained to my mentor that this high visibility of my work could also work in their advantage. If they'd consider using anti-plagiarism software like Ephorus, all the work turned in by students would be automatically checked against any papers findable through the web including mine.

I'll be honest and admit that having my work up on my site is also in part down to my sense of pride. I'm fscking proud of all the hard work I did last school year and I believe that my papers are also a testimony to my qualities in documentation and education. Call it my portfolio if you will.

I'll mull things over a bit and have another chat with my profs. Let's see if we can find some common ground in this. tags: , , ,

View or add comments (curr. 2)

The BoKS/Keon users group is taking off!

2008-10-29 09:44:00

About a week ago I opened up the BoKS Access Control users group (LinkedIn) on My goal was to unite BoKS/Keon admins from across the globe in order to build a tightly knit network in which we can all share our knowledge of BoKS.

The thing is, the way things are right now, there's hardly any information on the web about BoKS/Keon. First off "BoKS" is a four letter word, which makes it hard for Google to look for anything useful (especially since it keeps correcting it to "books"). Second, there's not that much on the web anyway! There's my website which has some real info and then there's the Fox Tech site which has general sales info. For some reason Fox Tech decided to hide all the manuals and in-depth stuff so only paying customers can get to the docs.

By building a professional network of BoKS users we finally know who to turn to for questions! LinkedIn allows us to post discussions inside our group and since folks from Fox Tech are also joining, we're bound to get some good answers!

Right now we're at 31 members but, since Fox has started advertising the group to their customers, I'm assuming we'll see a steady rise in members RSN(tm)! tags: , , ,

View or add comments (curr. 0)

Richard Fitzpatrick - "Euclid's elements of geometry"

2008-05-06 21:51:00

One artist's rendition of Euclid

A few weeks ago I wrote about my research on Euclid, the ancient Greek mathematician. Said research wasn't anything noteworthy, just something to form a basis for a biography written for a school assignment.

Back then I also wrote about a man called Richard Fitzpatrick and his remarkable work. You see, Mr Fitzpatrick took a nineteenth century translation of the Elements of geometry by Euclid and reworked into a new book. Each page of this book is split in two: one column with a greek text approaching the greek original and one column with a modern english translation. While the greek text doesn't add much for the budding mathematician, it does add a definite factor of "cool" ^_^

Mr Fitzpatrick's book can be downloaded for free as a PDF, but you can also buy a printed version from allows you to publish your own books at a very low price, which many academics and aspiring authors put to good use. $27 (including S&H) bought me a beautiful, hard cover book with an accessible translation of Euclid's Elements. The sleek, black cover looks quite nice and the fact that the book is printed on A4 paper makes it very easy to read.

Now... I shot some video while leafing through the book, just to give you an impression. The video came out a bit blurry, but that's what I get for using my compact camera under fluorescent lighting ^_^; tags: , , , ,

View or add comments (curr. 0)

Ephorus, anti-plagiarism software for teachers

2008-04-13 18:30:00

Recently, we were discussing a few anti-plagiarism measures over at the forums. Plagiarism of course being a rather stupid and bad thing to do if you want any form of education.

One of the checks so far is to just take any suspect sentences and plonk them into Google. This actually works miraculously well, seeing how Google indexes the hell out of half the Internet. The only downside to this approach is that you really only ought to apply it to suspected plagiarism, because you really can't copy and paste a whole document into Google's search bar.

To make things easier, some people have tried their hand at making a Google frontend, but with little success. So we'll have to turn to commercial companies who have their proprietary front ends and search methods.

Enter Ephorus, stage left.

Ephorus anti-plagiarism

On their website, Ephorus boast about their services like any good marketeer would. The emphasis in the following is mine.

Never search for plagiarism yourself again? An end to all irritations and qualitatively better papers? No problem. With Ephorus, you can prevent plagiarism with no extra effort. Moreover, with this anti-plagiarism market leader, you will be assured of the best service and the lowest prices. With Ephorus, teaching will be fun again!

Not only teachers and students benefit from Ephorus. Examination boards also see an improvement in the quality of papers. And since teachers no longer lose precious time investigating possible plagiarism, more time can be devoted to education.

Alright, sounds like a sales pitch, right? :) You'll notice that I bolded out two fragments that are rather important: they make it sound like Ephorus is the end-all-be-all solution to spot plagiarism. Sadly, this is simply not true. I'll explain this in a little detail shortly, but the gist of it is that Ephorus only checks materials they have access to through the Internet (eg Google search) and from their own database.

Ironically, their best source of original texts and information are their own clients. By submitting a document for verification, the customer allows Ephorus to keep said document in their database for future reference. This is also why recently students have been clamouring about copyrights on their documents. While teachers and schools are made aware of the fact that documents will be stored indefinitely, students are never told such a thing. The only thing they see is an upload form that asks for their details. No warnings, no disclaimers, no nothing. I guess Ephorus leaves that up to their customers.

The legalities behind all this are debatable. There's such a thing as fair use for academic purposes, but one could reason that Ephorus' goals are not purely academic.

Toying with Ephorus: a cursory glance

My initial impressions of Ephorus were good! The interface looks clean, well designed and calm. There's nothing there to confuse you and it's a good example of form following function. The interfaces is divided into a few sections:

You will find screenshots of most parts of Ephorus at the bottom of this page.

So far I've found a few small nags with the Ephorus online interface.

All in all I'm well pleased with the Ephorus interface. It's user friendly enough and is pleasing to the eye.

Testing Ephorus on some real documents

Of course, what would a software review be without putting it through its paces?

I've selected a few documents from my own schoolwork and a few other sources and I've submitted them to Ephorus. These documents are:

Analysis 1, DO10 One of my original works and never before published on the Internet.
Statistics 1, DO5 One of my original works and available on my website since last year.
Border-line op school A document written by one of my project team members at school. Never before published on the Internet. Also, at least 40% of the text was copied straight from books.
Pride and prejudice Well, we all know this book, right? The classic by Jane Austen which has been freely available on the Internet for years.

The first document came out as expected and only slight traces of "plagiarism" were found. It scored a 3%, 2% of which was accredited to other documents that I'd written. Ephorus has marked parts of my cover page and my student information as being straight copies, which isn't remarkable. The final 1% came from the fact that I had literally quoted one paragraph (properly cited by the way) from a book.

By turning up the strictness a notch, another 2% were added to my score. Apparently the words Maar dat was niet het doel van were found on two separate pages on the Internet.

The second document I'd submitted came out as expected as well: 96%. Of course, I'd expected a 100%, because the file itself has been on my website for over half a year now. So that's a bit odd. What's even stranger is that the cover page and information that was picked up for the first document wasn't flagged at all this time.

Disturbingly, my group member's document scored a measly 3%, in spite of his liberal copying. This can only be accredited to the fact that Ephorus cannot and does not search through books. Ephorus only relies on digital resources that it has free access to.

Finally, Jane Austen's Pride and prejudice was properly picked up at 98%. It would've been scary if Ephorus'd missed out on this ^_^

Personally, I think that the look and feel of the reports are just right. They could've been much prettier, or take the original document's formatting into account, but I reckon that would detract from its purpose. The reports offer just what a professor would need:

Fiddling with the strictness controls shows me that it modifies the amount of words that do NOT have to be similar in one sentence. By setting the level to "strict", Ephorus will also point out any lines that share a number of words (but not all of them) with another source.

In conclusion

Earlier, I promised to tell you why Ephorus isn't the end-all-be-all solution to plagiarism. And it's not something that only applies to Ephorus, but something that goes for all of its competitors as well.

This software does not search books, magazines, research papers and other published print.

Case in point: my classmates document came through fine. This means that teachers will always need to be on the lookout for plagiarism anyway. Ephorus and its ilk are just a first barrier that documents need to get through. And it's in that respect that I quite like Ephorus.

I'm glad that the Ephorus team gave me the chance to try out their software. I'm convinced that it makes a nice addition to the teacher's toolbox, even if it doesn't save him much work.














The Ephorus name and logo are of course copyright of Ephorus. All my screenshots were taken using the demo version of their website. tags: , , , ,

View or add comments (curr. 16)

Contacting Thomas Sluyter

2007-08-19 19:35:00

Recently we've been getting a lot of spam in our e-mail boxes, thanks to various bots grabbing our mail addresses from our contact pages. That's why we decided to put all the info in a .JPG instead. Sorry for any inconvenience.

Of course I also have a LinkedIn profile.

If you would like to send me an encrypted email, or if you would like to verify a signed email I sent you: here is my public PGP key

Contact info for Thomas tags: , ,

View or add comments (curr. 13)

Happy sysadmin day!

2007-07-27 10:55:00

It's the last Friday of July and you know what that means. It's Sysadmin Day, an international holiday on which end-users thank their admins for all their hard work! Or it would be, if anyone actually cared... *sigh* All I ever wanted was an STFU mug.

To all the sysadmins who -do- get some appreciation from their customers today: good on you! Enjoy your brief period in the lime light! ^_^ tags: , , ,

View or add comments (curr. 2)

Older blog posts