Ivan's Blog

I played with some more codings a few weeks ago: I turned the RDFS Closure algorithm of Herman ter Horst [1] into Python, on top of RDFLib. It generates the RDFS closure of an RDF Graph. Ie, triples that are inferred by virtue of RDFS Semantics can be then retrieved from the Graph. Combined with sparql-p, for example, it may be pretty useful… (at least I hope). I am sure there are still bugs, though

The code is a single Python file, but you can also download a distribution file containing the documentation. The latter is also available on-line.

[1] Completeness, decidability and complexity of entailment for RDF Schema and a semantic extension involving the OWL vocabulary, Herman J. ter Horst, Journal of Web Semantics, (2005) 79-115. Unfortunately, as far as I know, the paper is not available on-line. Category: /WorkRelated/SemanticWeb/RDFLib; Posted at: 15:50 UTC; Permalink

I listened to a long interview this morning on BBC World with Richard Dowden (executive director of the Royal African Society). The interview was on the problems of Sub-Saharan Africa in general. One of the issues that he raised (among many others) is the huge role the mobile has and will have on the further development of Africa. What he said, essentially (and resonates very well with what I learnt in India) was that the possibilities offered by the mobile may radically change African society though offering hitherto unknown communication means. And what is obviously an further aspect of this (though Richard Dowden did not refer to that) is that for most of the Africans the first experience of accessing the Web may be through their mobile. We may not be there yet, but we will be. Ie, to repeat what I said for India: the Web on Mobile is not some sort of a cherry on the cake for Africa as it is for us in the rich World, but it is the Web…

Unfortunately, at the time of writing this, the interview is not yet on-line on the home page of the BBC HardTalk series but I am sure it will be in a few days.

Category: /WorkRelated; Posted at: 09:57 UTC; Permalink

I spend a few days in the city of Trento, in Italy (I was invited to a Semantic Web Workshop), up in the Italian Alps. This turned out to be much more interesting than I anticipated, I must admit. This very nice small town is at the cross-roads of cultures: it is one of the few places in Italy (with Bolzano, somewhat to the north of Trento, and Trieste, on the Eastern Adriatic shores) which did not become part of the unified Italy in the 19^th century; instead, it remained part of the Austro-Hungarian Habsburg Empire until the demise of the latter in 1919. It is only at that point that these cities became part of Italy. Whereas Bolzano (ie, Süd-Tyrol) is really culturally Austrian (and this fact created quite a lot of turmoil after the second World War), Trento is Italian but with a distinct Austrian influence. This shows really well in the city, even when one has only a few days to see it. The style of the houses; the fact that they wear and sell “loden” overcoat, something so typical of the German speaking Alps; Austrian style coffee places, etc. It was very interesting and really nice. I have learnt something again…

Of course, I made some of photos; I have put a selection on this site. Enjoy…

Category: /Private/General; Posted at: 15:57 UTC; Permalink

I had the pleasure to be in Montreal for a few days, just when a post-Kyoto conference took place on Global Warming. The news I read on what was going on at the conference did not make particularly happy, with the US (and some other countries, like Australia) still opposed to any type of Kyoto process, with India and China dragging their feet to say the least, with Saudi Arabia having the guts to ask for compensation for the (insane) revenue it gains from oil… In some ways it is also very discomforting that the media do not seem to care either (in contrast to some attacks that try to present the issues of global warming as a media hysteria). Looking at Google News today, there is only one reference to a (rather good) article in the Independent. This is not Google’s fault: they simply reflect the number of news articles and the number of references to those. (To be fair to Google: if one looks at a search term on Global Warming, than there are of course more news. But they do not make it to the “top”.) I am not young any more, the effects of global warming may not affect me personally, but I am afraid for my son, for the children he might have one time, and for all the younger generation that will have to live with a terrible heritage…

There were also demonstrations in a number of cities. Including Montreal, and I was there when it went along rue St. Catherine. Sympathetic demo although, in fact, not that terribly big. But there were some nice banner, you can look at some pictures I took of them.

Category: /Private/General; Posted at: 15:26 UTC; Permalink

As I put it in another note, I spend a few days in India. An interesting phenomenon is the usage of mobile phones for accessing the Web. The fact is that the traditional infrastructure (electric, phone lines, etc) is in a pretty bad shape. As a consequence, a mobile phone may be the only way for people to communicate and, hence, to access the Web. There are villages in India, we heard, who buy a shared mobile phone line used by the whole community. Clearly, this is not an Indian phenomenon, I heard similar stories from South Africa, Brazil, of even my home country, Hungary. It is just that the numbers in India are higher…

This turns our perception upside down, in fact. We in the “West” (whatever that means) consider the laptop or the desk top as the primary access to the Web; the “Mobile Web” is a cherry on the cake rather than a real necessity. In India and elsewhere, it is just about the opposite! Hey guys, think about W3C’s Mobile Web Initiative: it may be of a primary importance for people across the World…

Category: /WorkRelated; Posted at: 01:37 UTC; Permalink

I spent a few days in India lately on the opening of the W3C Indian Office. Some amazing numbers we heard there: only 5% of the population speaks English properly, to understand Web sites, for example. The rest of the population is “spread” over 22 languages using 9 different scripts. Some languages practically do not have a Web presence. And we are talking of a population of about 1 billion. Speaking about the importance of I18N on the Web… Category: /WorkRelated/I18N; Posted at: 01:22 UTC; Permalink

Ha az újságokat nézzük akkor az, hogy ki csalt többet, Orbán vagy Gyurcsány? Ugyan ki akar foglalkozni az egyetemek állapotával, az általános rosszkedvvel, gazdasági bajokkal, stb. amikor, esetleg, lehet egy kis zsíros botrányt találni az ellenség (bocsánat, a politikai ellenfél) vezetőjénél? Elszomorító, hogy ez legyen a központi kérdés. Egyezzünk meg abban, hogy valószínüleg mindkét félnek voltak nem teljesen kóser anyagi ügyletei, és lépjünk tovább!

A szomorú, hogy ez a két marakodó társaság fogja talán alkotni az egyedüli két pártot a parlamentben a választások után. Habár… ki akarja, mondjuk, a Thürmer újraélesztett kommunista pártját, vagy a Jobbik-MIÉP koaliciót benn látni?

Category: /Private/Magyar; Posted at: 10:41 UTC; Permalink

I have just acquired a new CD. “New” meaning in a CD format: it is a remastered version of a recording of the sixties: the Mass in B minor of Bach (“Messe in h-moll”, if you want the original title), with Otto Klemperer, A. Giebel, J. Baker, N. Gedda, H. Prey, F. Crass, The New Philharmonia Orchestra and the BBC Chorus. It was published in the EMI series “Great Recordings of the Century”. If you love this type music, get hold of it. It is, in my view, the most formidable recording there is of this Mass.

(I knew what I was buying: I had the original version when I was young in the sixties, and I knew every note of it… I actually had conflicts with our neighbours because I played it too loud. And my record simply became unplayable over the years. Ever since I have a CD player I wanted to find this recording.)

Category: /Private/General; Posted at: 17:21 UTC; Permalink

The 2.2.2 version of RDFLib has been released, and this includes my old sparql-p as part of the distribution. Thanks again to Michel Pelletier.

There have been some small changes due to the merge. Whereas, in the separate sparql-p distribution, the main structure of the code was something like:

from rdflibUtils import myTripleStore
store = myTripleStore()
store.load("someRDFFile.rdf")
select = ("?a","?b","?c")
where  = GraphPattern([("?a",P,"?x"),(Q,"?b","?a"),("?x",R,"?c")])
result = myTripleStore.query(select,where)

the new version looks as follows:

from rdflib.sparql import sparqlGraph
sparqlGr = sparqlGraph.SPARQLGraph()
sparqlGr.parse("someRDFFile.rdf") # or sparqlGr.load, these are synonyms
select = ("?a","?b","?c")
where  = GraphPattern([("?a",P,"?x"),(Q,"?b","?a"),("?x",R,"?c")])
result = sparqlGr.query(select,where)

Not a big deal, but better be careful. I am sure that some other problems will pop up as we go, but this is a great start.

Work has also begun to include a SPARQL parser into the system, leading, eventually, to a full SPARQL implementation in RDFLib. That would be great…

Category: /WorkRelated/SemanticWeb/RDFLib; Posted at: 16:33 UTC; Permalink

It was a really good coincidence that I read the book of S. Huntigton, entitled The Clash of Civilizations and the Remaking of World Order, while being in Kyoto. Clearly a very controversial book, but certainly food for lots of thoughts (the Wikipedia entry gives a good overview of the book as well as the discussions around it, I do not want to repeat it here). Being in Kyoto at the time of reading it, i.e., being confronted to a very different civilization than what I am used to, made it even more interesting. And, of course, it is also related to my work: after all, the Web is a universal medium, and it would be very interesting to see whether the usage, the “ethos” of the Web transcends civilizations or not, does it act as a “unifying” force or, on the contrary, different civilizations look at the Web in very different ways. Of course, as long as the Web was used only by a very thin layer of the population in non-Western countries, these were not really issues; but things change. I am not sure whether there is any sociological work on this subject; would be interesting to do it.

Nevertheless, I also see the dangers of Huntington’s book; for example, it can certainly be exploited by racist theories and politicians like Jean-Marie le Pen or Filip Dewinter (and I am sure it happened already). Nevertheless, some of the statements of the book are worth remembering, like: “The West won the world not by the superiority of its ideas or values or religion but rather by its superiority in applying organized violence. Westerners often forget this fact, non-Westerners never do.” It would be wise if some members of the current US administration read the book…

Category: /Private/General; Posted at: 10:31 UTC; Permalink

A beautiful trip to the city of Kyoto, in Japan. Fascinating. Although the modern city itself is mostly ugly (at least in my view), the temples and shrines (which are all over the place) are amazing. We spent there 10 days and there were some new and wonderful thing to see every day. The art of combining architecture with nature (i.e., gardens) is simply amazing. Although I am not a religious person, I really had an almost spiritual experience in some of the Zen Buddhist temples. My only disappointment was with the National Museum in Kyoto. Although their Web site refers to a large number of things to see (e.g., in Far Eastern paintings), most of those were not on display. Pity… But I was compensated by the rest!

Of course, I made tons of photos; I have put a selection on this site. Enjoy…

Category: /Private/General; Posted at: 10:11 UTC; Permalink

The pictures on the TV are absolutely awful and terrible. But they also fill me (and people around me) with anger: one would have never expected to see such pictures coming from the US, even though the force of Katrina was bigger than what anyone has seen before in that region. It is incredible how that condescendent, arrogant, “who-if-not-me” crowd currently in power in Washington could be so powerless and blindfolded as they were in that case. I just cannot believe that, with more caring, better foresight, those thousands in New Orleans could not have been helped earlier and more effectively. Dicit the commentator on this morning’s BBC News (commenting on the long military convoy finally arriving to New Orleans): “a superpower who finally begins to act as one”…

In a number of countries Bush would have to resign after this. I do not believe we will be as lucky, though…

Category: /Private/General; Posted at: 09:20 UTC; Permalink

The horrible images of New Orleans and Mississipi; the report(s) on World Climate changes like, for example, the one issued by WWF and… a small discussion I saw on Fox TV a few weeks ago on the usage of SUV-s in the US, and that people should just use those. I wonder whether reasonable forces in the US will draw the conclusion of these terrible events, and that the pollution issues would be taken seriously, at last, on the US government level!

Category: /Private/General; Posted at: 16:21 UTC; Permalink

Úgy látszik, hogy az az álmom amire utaltam egy másik blogban egyre távolabb lesz a realitástól: lásd a legutóbbi Orbán és Kövér beszédeket…

Csak egy apróság: legjobb tudomásom szerint, egy bizonyos Orbán Viktor, a 80-as évek elején, megpróbált állást kapni az MSZMP KB Társadalomtudomány Kutatóintézetében, sikertelenül. Önmagában véve nincs ebben semmi rossz; azonkívül, hogy ez több mint 20 éve volt, az akkori környezetben az intézetben volt néhány igen kiemelkedő munkatársa bár, valószínüleg, ma az Orbán és a Kövér őket is hazaárulónak becézné. Hogy milyen hipokrit a világ…

Mindenestre, ha a Fidesz győz a választásokon evvel a stílussal, kevesebb kedvem lesz hazalátogatni. Hogy az ember odajusson, hogy az MSZP választási győzelmét kívánja (pedig nemigen szeretem őket sem), a magyar politikai helyzet anakronizmusa!

Category: /Private/Magyar; Posted at: 09:33 UTC; Permalink

Yesterday evening, courtesy of Arte TV, I had the opportunity to see this old movie again: produced by Costa Gavras, featuring Yves Montand, it came out 1970. The film itself is based on the autobiography of Artur London, one of the three survivors of the Prague Trials, the biggest and the last of the big Stalinist trials that sweeped through Central Europe in the early fifties.

It really got to me (again). I think that the book, together with Jorge Semprún’s “Quel Beau Dimanche” were among the most important (and terryfing…) books I read in the seventies on this subject, and were certainly part of myself becoming an adult. (That was in Budapest, Hungary, not in the well–protected “West”…) Yesterday evening also reminded me of those people that I knew (some of them very closely) and who went through similar ordeals; and of how extremely difficult it is to explain this Central European past to people who, either for geographical or for generational reasons, have no connection to those years. (To make it clear: I did not live through the fifties either, I am not that old, but that past was still very much alive when I was young…) Fortunately, all this is history now, let’s hope it will never come back in any form. (Hm. Sweet dreams, right? )

Category: /Private/General; Posted at: 07:36 UTC; Permalink

Egy kis ráadás az Orbán beszéddel kapcsolatos megjegyzésemre: Schöpflin Györgynek volt egy cikke a Népszabadságban. Ugyan a cikk nem minden kitételével értek egyet, de evvel igen: „Bár Fejtő Ferenc cikke jó pár tekintetben megkérdőjelezhető, mégis hasznos lehet, amennyiben elindít egy érdemi vitát a nemzetről és a baloldal nemzetfogalmáról.”. Schöpflin egy Fejtő cikkre hivatkozik, de lehetne egy Aczél cikkre is hivatkozni. Magyarán, legalább nívósan(?) is vitatkoznak egymással az urak… (hozzám, személyesen, az Aczél cikk áll a legközelebb).

Category: /Private/Magyar; Posted at: 08:41 UTC; Permalink

Külföldön élve az ember megpróbál, amennyire lehet, pártatlan lenni ami a magyar belpolitikát illeti. De, meg kell mondanom, az Orbán legútóbbi néhány beszéde és húzása sajnos kihozott a sodromból.

A washingtoni beszédek, bizonyos értelemben, hasznosak voltak. Világossá tették, hogy bármennyire is megpróbál „baloldali” attitűdöket felvenni, a Fidesz, illetve az Orbán, világosan a legkonzervatívabb jobboldal részei. Ez legalább egy tiszta ügy, és ehhez persze mind a Fidesznek mind az Orbánnak joga van. De hogy úgy hazudjon ahogy azt ott tette, az azért mégiscsak túlzás. Merthogy, az Orbán szerint, a Fidesz a valamikori, 1989 előtti Magyarország ellenzékének a letéteményese ugyebár. Már álljon meg a fáklyásmenet: én, úgy 20-25 évvel ezelőtt, nemigen láttam az Orbán nevét… Ami önmagában még rendben volna, hiszen fiatal volt. De én bizony olyan nevekre emlékszem mint Haraszti Miklós, Demszky Gábor, Szabó Miklós, Bence György, Kiss János, Rajk László, Tamás Gáspár Miklós… Hogy ezek közül vannak akik ma inkább a Fidesz-hez állnak közel, az igaz. Dehogy mindegyik… A valamikori Demszky, akinek volt vér a pucájában hogy szamizdatot szerkesszen és terjesszen, és vállalja az evvel járó meghurcoltatásokat, ma bizony az SZDSZ-hez tartozik, vagy nem? Szeressük vagy ne szeressük a Demszky-t (hogy ennél a példánál maradjak) vagy az SZDSZ-t az egy más ügy, de kisajátítani a valamikori „demokratikus ellenzék”-et intellektuális és morális disznóság.

De az Orbán utóbbi, tusnádfürdői beszéde sem rossz. Az az érzésem, hogy az ottani megjegyzése, hogy aszondja „amikor a baloldal erre időnként lehetőséget kapott, akkor rárontott a saját nemzetére” bevonul a magyar politikai elszólások történelmébe. Merthogy ugye a Kun, Rákosi, vagy az 56-os Kádár… Isten lássa lelkemet, megborzadok amikor ezekre gondolok. De egyenlőségjelet tenni a „baloldal” és ezek között azért olyan intellektuális és morális disznóság amit, megmondom őszintén, eddig nem feltételeztem még az Orbánról sem. Kiváncsi vagyok, mit szólna a konzervatív politikai elit, ha egyenlőségjelet tennének a konzervatizmus és, mondjuk, a Horthy fehérterrorja (ami azért nem volt semmi!) vagy a Szálasi rezsim között. Nem hiszem, hogy sokan örülnének. Márpedig a Szálasi is nekirontott ám a saját nemzetének, ennek, például, a magyar zsidóság kárát is látta…

Álmodok egy olyan jövőről, ahol a magyarországi belpolitika az emberi, morális, és intellektuális tisztesség keretén belül zajlik. Félek tőle, hogy erre még várnom kell…

Category: /Private/Magyar; Posted at: 11:01 UTC; Permalink

I had the pleasure of reading through an Introduction to Indic Scripts of Richard Ishida. It was a real treat and made me understand quite a lot of things. One aspect of internationalization I’ve learnt: forget about Chinese or even Arabic if you look for something complex; look at the various Indic scripts! Sure, Chinese has a huge number of characters, but if the font has them, than it is relatively simple. Sure, Arabic is bi-di, and characters have different shapes depending on where they are in a word, but again, this is manageable. But look at indic scripts: characters are either to the left, or to the right, or on the top, or at the bottom of the previous or the next logical character… a real mess! But exciting at the same time.

An ugly, racist, and awful remark… I wonder whether the relative simplicity of the Latin writing system (which, in this sense, is the same as Greek) has played a role in the scientific and technological advantage Europe has gained over the rest of the World in the 19^th century. It is certainly true that, say, Chinese writing can be an obstacle in getting knowledge to a large number of people. The same is probably true for Indic scripts (although not true for Arabic characters, in fact). An interesting subject for sociologists and/or historians…

B.t.w.: I18N is one area where Internet Explorer is way better than Mozilla or Opera. Only IE renders those indic scripts properly (and a number of other things like vertical writing or a proper line wrapping in languages like Thai). It is a pity that the Mozilla crowd has not taken that issue seriously yet or, better, that the community in India (and South East Asia, for that matter) has not joined the developers of Mozilla in a large enough number to get those things right. Actually, W3C has just opened an Office in India, maybe this is the way of get things moving…

Category: /WorkRelated/I18N; Posted at: 19:27 UTC; Permalink

Thanks to the enthousiasm of Michel Pelletier, sparql-p is now incorporated into the latest release of rdflib. Though not final yet, it should be in the main trunk soon when rdflib 2.2 comes out. I think this is the best possible outcome of my work and I am very grateful to Michel for this…

So: watch this space!

Category: /WorkRelated/SemanticWeb/RDFLib; Posted at: 14:30 UTC; Permalink

I had the opportunity to return (after 10 years) to the Monastery of le Thoronet in Provence. Absolutely beautiful. It is interesting to see that, at least for me, there is a certain similarity between this early Cistercite architecture and the Zen Buddhist monasteries I saw in Asia. The same approach: a strive for simplicity, seeking some sort of a spiritual experience without excessive ornaments, just by the pure forms, the “atmosphere” of the building, the close relationship to nature… I am not a religious person but these places do have a deep effect on me nevertheless. I could imagine spending several days at a place like that! (See, for example, the Wikipedia entry on the cisterian order…)

This reminds me of a fantastic TV series I saw 30 years ago done by the French TV, inspired by a book of Georges Duby called Au temps des Cath�drales (it was published in English under the title “The Age of the Cathedrals” in 1976), which retraced the history between the 10th and the 13th centuries through art, primarily architecture. It was beautiful, I have been chasing this series on DVD or tape for years without any success. If somebody knows where to find it…

Category: /Private/General; Posted at: 16:57 UTC; Permalink

I had the pleasure of having a trip to Japan and China again. Well, most of the time was on work, but I did have the opportunity to play tourist, too. So I made some pictures, of course both in Tokyo and in Beijing (some of those photos are old, look for the ones in May 2005). Here is the one I am proud of

Category: /Private/General; Posted at: 09:46 UTC; Permalink

I have made a small update on sparql-p: Version 2.02. There is practically no functional change (except for adding the ‘SELECT *’ shorthand and thereby getting the ‘ask’ method right); the main change is that the documentation has changed. I switched to epydoc, which gives a much better way of documenting the code with a javadoc-like output. That meant to restructure the interface description in the code, but it is (in my view) worth it.

B.t.w.: I was at the WWW 2005 Conference last week and it is interesting to see that there are already a couple of SPARQL implementations out there, most of them (probably) more complete than mine (first of all, they usually contain a SPARQL Language parser which I was always lazy to do . And people begin to use it for various purposes. That when the specification is not even in Last Call yet! Good…

Category: /WorkRelated/SemanticWeb/RDFLib; Posted at: 06:59 UTC; Permalink

I just came back from Gouangzhou (better known as “Canton” for Westerners), China. Quite amazing. A city of around 10 million people (so the locals said) and “only” the 5-6th city in the country (though, again, according to the locals it is the third most important city in the IT area after Beijing and Shanghai). The whole city feels as if it was built in the last 5 years (and it probably was, actually), booming, developing. It will be interesting to see when China will come out of the status of the “manufacture of the World”, and appear as a prime developer, innovator, scientific centre? (Although that might still take several years.) Nevertheless, it is clear that the bipolar World of the US and the European Union is soon over…

A lesson to be learned closer to home, by the way: I am a bit tired of the discussion around the referenda on the European Union in, say, France or the Netherlands. When will people realize that the only way for European peoples to stay around is via a united Europe? Otherwise, Europe is heading to become really the “museum of the World”, as one top man of Philips said not a long time ago…

Category: /Private/General; Posted at: 07:45 UTC; Permalink

I have ‘released’, so to say, an updated version of my SPARQL API for RDFLib. (As you can see, everything is in a CVS tree, so if you want to see previous versions, be my guest…

Lots of things have changed since the last release, including the API itself. This is because there are things I realized were wrong or simply awkward in the previous version. There are also some new features (eg, operators, datatypes). I have also added a Testing directory with a simple way of running tests; the directory includes a python version of almost all the relevant examples in the SPARQL draft. I must admit I have not made a systematic test yet with the official test cases; not having a SPARQL parser it is a pretty tedious process, because each query has to be mapped on the API manually. On the other hand, applications like the Talk management at W3C run with the renewed version for a while already, ie, the code is pretty stable, though may not abide 100% to the SPARQL draft yet…

The good thing is that there are several people who expressed their interest in taking over the development of the code and, eventually, merge it with the core RDFLib. This would be good for me but, I believe, for the Python/RDF community at large, too.

Category: /WorkRelated/SemanticWeb/RDFLib; Posted at: 14:42 UTC; Permalink