Monday 10 November 2008

[How not to] Design a computer network i.e. [how not to] take care where to place the wires; Bonus: Blogspot failed saving images for scheduled post

Don't worry, it's not that difficult!
Really, it's quite easy to place the wires of your network in the worst place possible. (Well, come to think about it, the worse one places the wires, the more notorious one's work gets!)

For example, Tuesday, when I had attended one of the courses at the faculty, I wanted to open a window for some fresh air, and what do you know? I bumped into the wires. Let me rephrase: the window bumped into the wires; they were placed up, on the wall, in a very creative and annoying position - check the images below:

It is quite funny, isn't it? Well, even engineers that design networks (and paths for wires) make mistakes, I guess.

Hmm, we have a Bonus Post: Blogspot failed at saving images for this scheduled post

Well, this post was written like 4 days before it's scheduled posting time. I checked it to be ok, I checked that the images were displayed correctly and so on. Then I scheduled it and forgot about it. When it actually got published what do you know? The images were not displayed correctly. I kept the links for original images just for fun - you can see them below... (and, yes, not seeing the images proves my point)

Thursday 6 November 2008

DigiTel ( Call Baring service = restrictionarea apelarii / parolare telefon

[Updated: 2010, when I noticed RCS&RDS changed the links]


Should one live in Romania and have a telephone land line through DigiTel (that's the name of the service offered by the RCS&RDS company), then it might be useful to know how to use the Call Baring Service.

I've searched the site DigiTel (name changed since 2010, probably) for the English version of the pages I am about to refer, but I haven't found them.

The Romanian version for the Call Baring Service - the actual Call Baring Service description for telephone users.


Pentru telefon prin DigiTel: restrictionare apeluri (fix, mobil, international) / parolare telefon etc. => informatii utile, solutia etc.

Solutia efectiva cap-coada (comenzile disponibile). Practic, intai faci activarea initiala a serviciului, apoi iti schimbi parola initiala 0000 in ce vrei tu din 4 cifre, apoi iti alegi o restrictie, activezi restrictia si gata; cand vrei sa suni undeva in zona restrictionata, dezactivezi restrictia, suni, apoi reactivezi restrictia. Simplu!

Sunday 2 November 2008

Solution: Remove/Delete JPEG metadata / header information


One needs to modify/manipulate the header of .jpg files, i.e. one needs to remove / strip out / delete the metadata from those JPEG images. Obviously, one would need some sort of a tool to do that. So, I searched for something/anything to help me.

Solution 1: Jhead

I found (in 2008) this little command line tool called Jhead (documentation can be found here) which helped me get the job done.

Thank you. It's simple and has done exactly what I needed it to do.

Solution 2: exiftool (perl)

I found it in 2010 while reading Mat Cutts's blog post How to strip JPEG metadata in Ubuntu.

Thursday 30 October 2008

ImageMagick (convert), GhostScript (gswin32), GSview

To put it simple, I was trying (under Windows XP SP2) to convert a .pdf file into a .jpg file, to upload it on my personal blog.

ImageMagick is quite a good tool. I've been using it under Linux (Kubuntu) and Windows at various projects (i.e. at my diploma project, to convert some images into pdf files; at a project done as a homework for a course, called ASDN, at the faculty - my application had to recognize letters from that type of images used for login / create account and I was using neural networks as part of the solution and I used ImageMagick to play a bit with the images before actually running my algorithm etc.)

Since when I worked at my diploma project I used ImageMagick to convert .gif files into .pdf files and it worked, I supposed the opposite would work flawlessly today. Well... no. When I tried to convert a .pdf into a .jpg it gave the following error:

convert: `%s': %s "gswin32c.exe" -q -dQUIET -dPARANOIDSAFER -dBATCH -dNOPAUSE -dNOPROMPT -dMaxBitmap=500000000 -dEPSCrop -dAlignToPixels=0 -dGridFitTT=0 "-sDEVICE=pnmraw" -dTextAlphaBits=4 -dGraphicsAlphaBits=4 "-r72x72" "-sOutputFile=C:/DOCUME~1/john/LOCALS~1/Temp/magick-jTzLRJ_C" "-fC:/DOCUME~1/john/LOCALS~1/Temp/magick-TlaNdwxx" "-fC:/DOCUME~1/john/LOCALS~1/Temp/magick-NkbgXR1g".
convert: Postscript delegate failed `myFile.pdf': No such file or directory.
convert: missing an image filename `myFile.jpg'.

^note: I replaced my actual filename with myfile.

One can imagine I was quite surprised when the error showed up in the command line. Ok, hello little error, let's see what upset you...

After searching a bit on the Internet (thank you, Google) I realized the solution was the following:
  • Install GhostScript for Windows:

  • Optional: install GSview for Windows: - well, since I got so far, why not? It could be usefull sometime in the future... I mean, I have no viewer for .ps or .eps files (ok, for .pdf I have a viewer), and I've always wanted a viewer for those 2 file types, in fact it's been my secret desire for about 2 years now but I've never told anyone; ok, I admit it, I was too lazy to search for a .ps viewer and always clicked on the .pdf version of the same file.

  • Run the convert command at the command line (convert is the mighty and powerfull ImageMagick) as I've tried before and get my job done.

Now, wasn't that simple or what?
Why did I get nervous in the first 15 minutes, mmm?

Ok, I admit it, I faced another tiny little problem after that: the default DPI seemed quite small (I drew this conclusion because some elements, i.e. characters and numbers in the .jpg output looked bad), so I had to increase the DPI in the output. This should help you get the job done.

After some attempts, I decided a 350x350 DPI is enough for me; yes the command was something like:

convert -density 350x350 inputFilename.pdf outputFilename.jpg

And yes, it worked.

Hope this helps you. Keep having fun with technology! ;)

Tuesday 28 October 2008

Fall Semester (Odd/Even Weeks, Calendar) for MSc. Courses (Politehnica University - Bucharest, Computer Science Department)

Romanian: Organziarea saptamanilor (pare si impare) si Activitatile pentru semestrul de toamna al anului universitar 2008-2009, cursurile de Master, Universitatea Politehnica - Bucuresti, Facultatea de Automatica si Calculatoare.

Friday 24 October 2008

Coperti pentru lucrarea/proiectul de diploma

[This post is in Romanian since it's a guide to few of the places where one can find covers for the diploma project]

Acest post sintetizeaza locurile de care stiu si pe care eventual le-am testat, cu scopul de a rezolva o problema clara si clasica: coperti pentru lucrarea/proiectul de diploma; locurile de care vorbesc sunt o compilatie intre locurile in care am cautat in vara si locurile de pe Bd. Kogalniceanu indexate acum in toamna, cand mi-am mai scos o copie pentru sufletul meu de inginer.

Bulevardul Kogalniceanu (acela care pleaca de la Piata Kogalniceanu si merge pana la Eroilor) - sunt multe xerox-uri aici pe bulevard si cea mai buna metoda este sa intrati in fiecare si sa intrebati. Acum, in toamna, coperti se faceau la:
  • nr. 21: astepti 3 zile si platesti 32 RON; culori disponibile: negru, albastru, rosu

  • nr. 37 (CONY): astepti 3 zile si platesti 35 RON, deci mai scump

  • nr. 55 (ultima cladire, in fata Facultatii de Drept, langa BRD): aici au prindere la rece, pe sina (şină) - e alta metoda decat prinderea clasica cu suruburi sau prin lipire; sina se pare ca tine destul de bine - pe mine m-a convins demonstratia in vara si, fiind si in criza de timp, acolo mi-am facut atunci. In vara pretul era de 35 RON, acum in toamna vad ca a urcat la 40 RON pentru asteptare 3 zile; acum cand am intrebat nu mai aveau sina culoarea neagra, dar in vara mi-am facut cu negru - o fi sezonul slab in perioada asta si de-aia.

Anyway, acum am vrut sa-mi fac la cei cu 32 RON, dar am aterizat aiurea la CONY. Mi-am printat lucrarea la nr. 47-49 "xerox cu caine" (intr-adevar, ciudat nume au oamenii astia, cred ca au vrut sa-si impuna porecla), unde mi-am printat in Mai lucrarea pentru sesiunea de comunicari, dar acum ultimele 30 de pagini le-a scos greu, adica aproximativ juma de ora, nu stiu ce a avut imprimanta aia. Fiind si seara, si plictisit, m-am trezit apoi ca intru la CONY, dau comanda, platesc si abia atunci realizez ca am gresit locul; eh, asta e. Partea buna e ca a iesit frumos: coperta neagra, scris auriu, foile lipite bine, am si fir de-ala alb pentru semn; ca sa nu mi se murdareasca la ei in xerox pana am luat-o, au pus-o intr-un pachet gol de hartie (din acela de 500 coli, clasic) - mi-a placut asta.

Regie: pe la xerox-urile de la parterul caminelor.

Piata Romana: fix la coloane exista un xerox si se poate da comanda si pentru coperti acolo; in vara, cand am fost eu, era o foarte mare coada acolo; deh, toata lumea vroia sa-si faca in perioada aia coperti!

Am mai inteles ca exista ceva pe langa (sau in) Magazinul Cocor, nu mi-e clar; oricum, asta-vara, cand am ajuns la Cocor si am realizat ca e in reparatii am plecat rapid de acolo si n-am mai indexat zona.

Sfaturi/Informatii suplimentare:
  • Preturile sunt pentru asteptare 1-2-3 zile, depinde cum vrei; evident, pretul variaza invers proportional cu timpul de asteptare.

  • In perioada cand termina toata lumea, adica in vara, se aglomereaza rau de tot peste tot, si ar fi bine sa aveti o saptamana in care sa alergati dupa coperti ca sa nu va treziti in pom; really, in Regie, de exemplu, am auzit de la colegi ca centrele xerox refuzau comenzi, iar inainte de asta garantau un timp de 5 zile pentru creearea copertilor; pe Bd. Kogalniceanu, cei cu coperti cu surub sau lipite mi-au zis ca degeaba platesc taxa de urgenta, ca dureaza minim 3 zile ca sunt prea algomerati cei ce le fac. => De aceea am facut cu sina atunci. (Acum, in toamna, lejer, nu e nimeni - well, nu termina nimeni facultatea acum!)

  • Eu am preferat sa-mi printez lucrarea acolo unde exista si xerox-uri - m-am gandit ca iese mai frumos decat acasa; inceputul (care contine sigla facultatii si a unviersitatii) l-am printat color.

  • Modalitati de legare a lucrarii intre coperti: cu surub, cu foile lipite (cum sunt agendele), cu sina (şină).

Sunday 19 October 2008

SAAI + SPBA, Subiecte (comune) Admitere Master, Septembrie 2008

M-am gandit ca ar fi util sa pun pe net subiectele pe care l-am avut la admitere master, poate are cineva nevoie la un moment dat:

SAAI (Sisteme Avansate pentru Aplicatii Internet) + SPBA (Sisteme de Programe de Baza)
Subiecte (comune) la Admitere Master, 2008-09-19
Facultatea de Automatica si Calculatoare
Universitatea Politehnica, Bucuresti

Subiectele au fost comune pentru cele 2 specializari, si cuprind 3 domenii:
  • Protocoale de Comunicatii

  • Retele de Calculatoare

  • Baze de Date ("Baze de Date" e numele general pe care-l pun in programa, DAR daca citesti atent programa, vezi ca de fapt sunt cerinte si din cursul de Proiectarea Bzelor de Date, facut la C3; precizare: pentru cei ce fac 4 ani, pe noua programa la C3, cred ca se numeste Baze de Date 2)


Protocoale de Comunicatii:

1. Protocoale de transport: stabilirea conexiunii, eliberarea conexiunii, prevenirea congestiei. (cred ca se vroia pe cazul general, asa cum e descris el de Tanenbaum)

Retele de calculatoare:

1. Comparatie Ethernet vs. WLAN. Se dadea un tabel cu 3 coloane de forma " | Criteriu | Ethernet | WLAN | ", iar tu formulai criteriul, apoi spuneai ce se intampla la Ethernet, respectiv la WLAN. => in felul acesta comparatia era cat de cat structurata (a fost o idee buna, intrucat asa nu mai puteau bate campii cei talentati la asta).

2. Se dadeau multe protocoale, din toate nivelurile OSI => cereau sa specifici la ce nivel al standardului OSI functioneaza fiecare protocol.

3. Erau date 4 adrese IP cu "/" si se cerea sa spui care-i prima adresa, care-i ultima, cate host-uri sunt in total.

4. DHCP.

Baze de date (aici totul a fost de fapt din cursul de PBD)

a) Ceva cu RLOCK/WLOCK, peste care eu in curs am sarit ca mi s-a parut aiurea. Teapa!

b) Cu RLOCK-UNLOCK si WLOCK-UNLOCK si graful de precedenta: sa explici, sa le spui algoritmul, sa exemplifici etc. ("Baze de Date" e numele general pe care-l pun in programa, DAR daca citesti atent programa, vezi ca de fapt sunt cerinte si din cursul de PBD).

Timp de lucru: 1:30:00, mhm, adica 90 de minute.
A fost de scris multisor, intr-adevar, iar timpul a fost si el pe fix.
Recomandarea mea: ar fi bine sa mai faci exercitii de scriere pe acasa, in timp ce inveti, ca sa ai mana exersata.

Bun, le-am scris ca sa le pot uita acum :)

Saturday 4 October 2008

The new Facebook: "This Box cannot be added to the Wall tab"

I have written some time ago about the new Facebook interface and two of the tabs that gave me headaches: Wall tab and Boxes tab - the issue, as I've described it then, was that I could not move neither "iRepresent", nor "Honesty box" from the Boxes tab to the Wall tab. (I filed a a bug report at that time, since I thought that to be a bug; however, I have not received a reply since)

Today, after playing a bit inside my Facebook account, i.e. surfing the settings and various options that the profile offers, I accidentally reached the Boxes tab; when I clicked on the little pencil shown in the upper right corner (in both "iRepresent" and "Honesty Box"), I discovered that besides the usual "Remove Box" message, I received an extra message: This Box cannot be added to the Wall tab

So, it was not a bug, it was a feature :D However, I still want to move these 2 boxes to the Wall tab, and I hope that some day they well allow the move.

Update: To the right of all tabs, there is that "+", which, if one clicks on, offers the possibility to add as a separate tab some of one's boxes; so, I took advantage of this option and added the "Honesty Box" as a separate tab; however I also keep it in the "Boxes tab". It's worth to mention that "iRepresent" cannot be added as a separate tab.

Friday 15 August 2008

To do: add the Digg yellow button

To do: add the Digg yellow button to all my posts on both my personal blog and my computer science related stuff blog.

I did some research on the net (i.e. googling) => I found 2 solutions:

  1. The first solution is exactly what I was looking for. Thank you, Jorge!

    Of course, there's also Digg's solution but it's not very straightforward to find - I mean the thing that I wanted with the button seems quite difficult to find. I found it on their website only when I knew what I was looking for. However, they don't say exactly how to integrate this with blogger: I have searched quite a bit on and I'm quite sure that they don't say anywhere on their site the exact specific way to integrate digg with blogger - I mean the exact specific information as I needed and Jorge's blog provided.

    The funny thing is that googling digg for the exact integration with blogger only offers results about digged web pages and none from Digg Help.

  2. The second solution I found is for adding digg buttons to individual posts. I haven't tested that, because I didn't need it and also I don't have access to a server where to store that html file they're creating as a workaround.

Hope this helped anyone trying to add a Digg yellow button on their website!

P.S.: Now guess who's the first one to digg my personal blog! Yes, obviously, it's me!
P.S.2: Yes, yes, I know and I've read that technically they don't accept non-English digged links, but hey! it would be a real shame not to promote those posts I wrote about my traveling in Romania.

Tuesday 12 August 2008

The new Facebook

I haven't logged into my Facebook account for quite a long time now: 1 week or a bit more.

Anyway, it seems they have been working to their new interface, which I ignored until now, but today when I logged in I received a message (written by Mark Zuckerberg in person! - ha-ha-ha... come on, it was fun, Mark himself signed it...) asking me whether I would like to try it out. Ok, sure! Let's give it a try! So, I switched to the new interface, and played with it a bit and a bit more...

I find the new interface cleaner and simpler, indeed. It was a bit confusing at first, I admit, but on the other hand I suppose that's natural since everything is somewhere else now. Ok, I kind of like it for now.

  1. The "Wall / Info / Photos / Boxes" tabs are a good idea, since it keeps everything simpler. That I definitely like.

  2. I must say that I have successfully moved the "Super Wall" and the "Slide FunSpace (formerly Fun Wall)" to "Boxes" tab - yeeey!, I finally placed them somewhere far to bother me less! - in my old profile I placed them at the bottom, so they were far again. "Super Poke" was placed in "Boxes" tab from first - thank you, good choice!

  3. I also tried to move from "Boxes" to "Wall" my "I represent" (I very much like to state that I represent Romania) and "Honesty Box" boxes - I couldn't find a way to do that and I supposed it was a bug so I filed a bug report - hmmm...

    I have successfully moved "Fun Wall" and "Slide FunSpace" from "Wall" to "Boxes" tab.

    I would like to move "I represent" and "Honesty Box" boxes from "Boxes" to the "Wall" tab, but I don't seem to find a way to do that - clicking on the little pencil in to upper right corner of each of these 2 boxes only displays "Remove Box", but not "Move to Wall tab".

  4. They are still working at it and also ask for feedback - so, people, feedback if you'd like it changed! Anyway, Super Wall is still in progress - let me quote them: "We're currently upgrading Liviu's Super Wall to make it better and faster. Click here to check the latest upgrade status."; ok, I clicked the link, and now let me quote some more: "Please check back in a couple hours and everything should be good." => some half an hour later, everything was ok, indeed.

  5. The "Create a Profile Badge" feature is interesting. I might even make one in the future and post it on, I don't know.

All in all the new interface seems somewhat better. I will stay with it for the moment. And I hope they provide me a way to move "I Represent" (and optional the "Honesty Box") to the "Wall" tab.

Wednesday 16 July 2008


Situation: from time to time one needs to move big files (~100-800 MB, so you cannot attach them to e-mails) from one computer to another over the Internet. Of course, there are various solutions that can be used: either install a real/complex server, or use ftp, or DC++, or use dedicated websites that allow uploading big files for them to be later downloaded (they offer password protection too), or using the file transfer included in instant messaging clients (in Romania most people use YM, but I use an older version of Trillian Pro and they're not compatible when it comes to file transfer) and so on.

Mircea suggested a lot of time ago that I could use HFS - he has been using it that time for a few file transfers and he was satisfied by it; just as he did, I downloaded it from

To put it simple, the best thing about HFS is that you simply start it, add what you want to be downloaded/shared, give the link to a friend to download the file and when you're done, you simply close it. (there's no need to install anything; as I've already told you it's a simple solution - and it works; should you need a more complex solution, do install a complex server, like Apache for example)

So, since then I've been using HFS from time to time to transfer files between me and my friends.

Today I was forced to discover an exciting new feature of HFS: you can also use it for uploads. I followed the steps explained here and it worked just fine. (The problem was that at the other end the user had no control over the public IP and only accessed the Internet over NAT. Normally, when the other user needed to transfer a file to me, he/she started its copy of HFS and I downloaded form him/her; however, now the NAT thing didn't allow for that.)

Conclusion: it's a good piece of software. I recommend it.

Sunday 29 June 2008

Graduation Festivity

Yes, I finally and eventually and happily graduated! 28th of June was the big day when our graduation festivity was planned to take place.

Yeeey! It was a tough journey through 5 years of college here at the Faculty of Automatic Control and Computer Science from "Politehnica" University (Bucharest).

The university prepared quite a nice festivity for us: well organized and with many good speeches (ok, there were 1 or 2 bad speeches, but maybe I just didn't like them). I liked the festivity overall; it made me feel good. Besides, it took place at Sala Palatului (Palace Hall, which is a location that I very much like) here in Bucharest.

The university borrowed us black robes, black square-shaped hats and scarves; the colors of scarves and balloons that we wore were supposed to represent the college we came from.

I met a great part of my friends from faculty: from former classes I took in faculty (they split our original class at one time according to the direction we wanted to study; I also took some optional classes meanwhile studying my primary direction) and some from high school. Unfortunately I couldn't enjoy the festivity near all my good friends from faculty since some of them were studying for their diploma project abroad and they'll be coming back at the end of July.

The festivity ended with a short concert (50-60 minutes), but we hardly payed any attention: everyone was too busy talking and making pictures. Hey, one usually graduates once, so we must use at best that time!

My favorite picture of all, is the picture representing myself (of course!) happy (of course!) right after the graduation festivity (obviously!).

I still cannot believe it. Technically, I AM ENGINEER now. Oh dear, life is getting serious...

Sunday 4 May 2008

Hello again

I need this post to run some tests and check some monitoring stuff from my Analytics account and so on. See, I'm working hard to make this blog really nice and well monitored and analyzed. And I do it all for you, my readers... I can see you blushing... :)

Friday 2 May 2008

Hello World

What better way to start a blog than the well-known "Hello World!"? I'm glad you agree with me. Good. There's a good chance that you might even like what I'll be blogging about.

If you like what I blog about, then keep coming and keep reading my blog.
If you don't like what I blog about, then keep coming until you like what I blog about.

=> Therefore, the best choice would be to keep visiting my blog. (Feel free to subscribe!)