| Capitalist environmentalism |
[Apr. 30th, 2008|06:09 pm] |
While I could be considered concerned about the environment, I am by no means a tree-hugging hippie. For instance, I firmly believe that alternative energy sources should be economically feasible before being implemented for large-scale energy production.
For instance: how much does it cost to build and operate a windmill? How long will it last, and what is the value (price) of the energy that it generates? I know that ten years back, this sum yielded a negative result: the windmill itself was more expensive than the energy it generates. Using windmills back then was not a wise decision. I must admit I don't know about the current situation. With advances in engineering, it is quite possible that windmills are now feasible.
I think that, as 'traditional' energy sources become more expensive because of increasing consumption and, hence, shortages, the alternative sources will become viable. Subsidies are unneeded and, indeed, unwanted.
With respect to electronics, the tipping point has been reached. With increasing demand for stuff like gold and copper, the prices have gone up. This has made it viable to recycle discarded electronics -- not to spare the environment (though that is certainly a welcome side-effect), but because the recycling plant produces as much raw gold as a small goldmine. Recycling is, literally, a goldmine.
I think this is incredibly cool. |
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| Robotics |
[Mar. 19th, 2008|08:29 pm] |
Four-legged robitics enter the uncanny valley.
If they manage to mass-produce these for a cost that makes 'em semi-expandable, stick a weapons platform on it and equip it with a GPS, you could just air-drop a robotic army someplace inhospitable. Come back a week later and pick off the survivors, and you're done... |
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| Not-so-random number generators |
[Nov. 15th, 2007|08:02 pm] |
For cryptographic uses, a random number generator is a must. Obviously, if all you have is software, your best effort will only produce pseudo-random numbers: if you know the state of your RNG, you can predict which numbers will be produced next. Luckily, for most cryptographic applications, attackers can not inspect the state of your RNG -- all they have is the bit sequence. And if the RNG is 'sufficiently' random, that can not be used to deduce the internal state of the RNG.
It turns out that the RNG in Windows 2000 (and perhaps other versions of Windows) contains a vulnerability that will allow an attacker to deduce the internal state of the RNG. So any crypto based on randomness from that RNG is vulnerable.
There are more algorithms to produce random numbers. A set of such algorithms are currently undergoing discussions to become part of a NIST standard. Curiously enough, the NSA has pushed for the inclusion of a particular algorithm. That algorithm, called Dual_EC_DRBG, is about three times as slow as the others. And it contains some magic numbers that are used as a seed.
As it so happens, some eggheads did the math, and concluded that there is a second, hidden set of magic numbers that complement the published set -- and with that second set, one can perfectly predict the state of the RNG itself. Bruce Schneier has interesting things to say about it.
Would there be a market for a robust hardware RNG? Perhaps something one could plug into their USB port or something? What kind of APIs would such a device have to offer to be of use in everyday security applications, such as generating GPG keys and such? |
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| Hacking Javascript |
[May. 25th, 2007|10:46 pm] |
This week, I have been hacking a site together for ![[info]](http://l-stat.livejournal.com/img/userinfo.gif) ingiechan's photo expedition.
She gave me a raw sketch of how it should look, and how it should behave. Re-using the CMS I wrote for Creative Contraptions (which still isn't online) for this site would be overkill and require some rework of the system, so that was not a viable option. But building every page by hand also was not an option.
So I devised a cunning plan to create a site that is completely built up through DHTML. Specifying the site structure is only a matter of calling a Javascript function repeatedly with the right parameters -- something that ingiechan can do herself. Maintaining the site then doesn't require any intervention from me, as it should be.
I decided to take the plunge and use Javascript OOP (or maybe I should call it 'OIP': Object Inspired Programming...). Works pretty well, except for one quirk that took me an hour to solve.
If you have an Array of objects, you can traverse the array in two ways: either you use a for-loop with an integer to index every item in the Array, or you use a "for (var x in Array)" construct. In the latter manner, your variable is not recognised as an Object -- but in the first, it is.
Why this is, is completely beyond me. |
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| Location doesn't matter anymore |
[Apr. 11th, 2007|09:49 pm] |
During the DotCom bubble, people were constantly blathering about how location would become meaningless, because all computers would be interconnected and you could hackaccess any information from any location.
Then the power situation in California went all haywire, with rolling blackouts and whatnot. If you have your server center located there, you're paying the price. Location does matter: you need the right infrastructure.
But once the infrastructure is in place, location indeed doesn't matter anymore. If you can get your server center powered, cooled and maintained, it doesn't matter where it is located.
Enter Iceland.
Iceland has virtually free power (because all you need to do to get steam is run a pipe into the ground), highly qualified personnel, and it is located on top of several optical backbones between the US and Europe.
What's not to like? |
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| BoFH versus GPS |
[Apr. 6th, 2007|08:54 pm] |
Everyone who has ever manned a helpdesk (or called one) knows the Bastard Operator From Hell: a powerhungry individual who dislikes his customers and does everything to get them off the phone with any lame excuse he can come up with.
One famous example of an excuse why someone's computer is slow to boot up is: "sun spots".
Seems like that is actually a reasonable answer as to why your GPS receiver loses its fix. |
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| Glonass |
[Apr. 5th, 2007|07:02 pm] |
The Russians are busy building their own satellite positioning system, called 'Glonass' (short for Global Navigation Satellite System). (As an aside, why is it that everyone seems to think that navigation is the only thing you could use a positioning system for...? And I'll bet that the Glonass signal doesn't provide routing information at all -- that will be left to the device!)
An interesting development. Suppose you have a three-in-one system that can receive GPS, Glonass and Galileo signals -- would the overlap in signals increase precision and performance? How do the signals compare? Would adding this new system to an existing GPS chip set increase the complexity dramatically?
Also of interest is that this is a military system, just like the GPS system is. However, it is improbable that both systems will be distorted in exactly the same way at the same time -- which means your receiver would still work in Iran... |
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| Parents and Computers |
[Jul. 19th, 2006|09:23 pm] |
My mom is doing a course to learn to use computers. Obviously, I get called every once in a while to help her with setting up/configuring the programs she uses. Sometimes I can walk her through ticking a checkbox, but often she fails to convey what is happening on the screen and/or I fail to understand what she sees happening... Perhaps I should configure her machine for remote assistance because that would allow me to, uh, assist her remotely. :)
I made her an email-adress as well, so now once in a while I get an email from her, which is a lot of fun!
She asked for the URLs to my and ingiechan's Journal -- I now realise that we post quite a bit of interesting stuff under friendslock, so we might want to make her an account here. paultje has one too, simply to be able to keep up to date with us. |
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| I pwn technology |
[Jul. 7th, 2006|09:51 pm] |
Yesterday, our TV died.
So it is time for a new one. We have been pretty content with our 4:3 70cm stereo TV, and frankly, I don't want anything else. Widescreen is fugly, and the really large TVs have to conduct some trickery to fake the pixels that just aren't there in the PAL signal.
I don't want a 'HD ready' TV either. The whole HD thing is still in its infancy, protocols and specifications haven't been set in stone yet. Sure, HD is beautiful, but I don't have any HD content anyway. And how many people have bought a 'HD ready' TV without HDMI? I'll buy one in five years, when HD content is common and the technology has matured -- I'm not going to spend hundreds of euros for a device that I may or may not be able to utilise to its full effect in the future.
The TV I want is a curious beast -- too big to fit in the bedroom (where a lot of 'secondary TVs' end up, and surely you're not going to buy an expensive widescreen LCD TV just to watch a soap in bed?), but not 'advanced' enough to compete with the LCD widescreens.
I had found a TV I would want (a Philips that gets high marks -- our 'old' TV was a Philips as well), but it wasn't in stock -- and we would have to wait until the 20th to get it... And the JVCs they had, wasn't in stock either, and they got low marks for the speakers...
So no TV for us right away. Tomorrow we'll conduct an expedition to the city centre.
However, that doesn't mean all is lost. Remember, the MACH F is a computer! So I got ingiechan's old 17" CRT monitor from the attic, hooked up her 2.1 speaker set, and we could continue watching! Sure, not as big as we were used to (which was a bit of a pain with stuff that's subtitled really small), but at least it all works.
Sometimes it's a bit of a pain that the MACH F is less of an 'appliance' and more of a PC, but sometimes it all works out beautifully. |
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| Shopping for phones |
[Jun. 11th, 2006|10:16 am] |
So, I want an iMode-telephone. KPN has a really cheap 'internet on your mobile' plan, which is lots and lots cheaper than all the other offerings (as in: 20 euros less per month, and the phones are free at that price!) Sure, it's not the whole of the internet (you have to use cHTML, a subset of HTML), but it works.
So yesterday we walked into the local KPN shop and asked about the phones. There were some competing models, some having more features than others. Enough choice there. The salesman asked why I wanted iMode, so I told him I am working on a webshop and that I want to be able to check up on orders via my phone. I also told him that I knew what goes into making an iMode-site, because I built the Volkskrant iMode site.
He nearly flipped out. Apparently he had never realised that someone has to make these sites before you're able to watch them on a phone.
He also asked me if I cared about soccer. Because if I did, they had a subscription plan that included a year's worth of free access to the Voetbal International iMode site. I dismissed this -- I don't have any interest in soccer, but if I wanted to read that site, I can do it at work, because guess what? Yes, we made the VI iMode site as well. :)
So now I have to find out how quickly I can get rid of my Vodafone plan, and set the wheels in motion. |
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| How couples surf |
[Jun. 6th, 2006|06:17 pm] |
imomus was writing an article for Wired about the surfing habits of "information couples", and he asked people what their habits are in this respect.
I think we fit the bill pretty well. I spend lots and lots of time behind the screen (both my work and almost all of my hobbies make use of a computer), and ingiechan is slightly less bad but is getting there.
The best decision we made with respect to our flat (where we lived before we bought the house) was that the computer(s) had to find a place in the living room -- this enabled us to spend lots of time in the same room: me behind my computer, ingiechan in front of the TV. I don't know if our relationship would have been as strong as it is today without that -- the constant possibility to communicate with your partner is important to us.
When we were looking to buy a house, we expressly stated the possibility of computers in the living room as a requirement. Sure, it gets messy (stuff tends to accumulate around/on/beneath my desk), but the benefits are much more important. We did dismiss some houses because the inability to fit both a sitting arrangement and a computer desk in the living room.
Which is why our current house is ideal: we can close the sliding doors to hide the computers from view, but if we open the doors we have a single large space.
Our desks are at the font of the house, next to each other. This makes it easy to communicate when we are both at work on our computer. We use MSN to pass URLs to interesting stuff to each other. We don't do 'cute' things like mail or chat via the internet when we are a mere meter apart.
My computer (and to a slightly lesser extent, the internet) is a very large part of my life. More so than ingiechan's, but I think she rarely feels like an 'information widow'. I had to learn that some things are less important than others, and I try to be attentative to her needs and/or words (though I have to admit that I sometimes fail at that, especially when engrossed in something).
We both have permanent LJ accounts, so I think in the end it neatly evens out. |
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| Weekend / Telecom |
[May. 8th, 2006|07:38 pm] |
The weekend was busy, but fun. We cleaned the house pretty thoroughly, because isthar and R. would come for dinner on Saturday, but more importantly, ingiechan's parents, sister and grandmother would come to visit on Sunday.
There's not much to tell about that, other than that everyone had a good time.
Also, I am amazed at how hard it is to get a clear and unambiguous overview of the prices of mobile phones and the associated calling plans. All providers want you to visit their shop, it seems. |
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| Turn your TV off! |
[Apr. 26th, 2006|11:05 pm] |
We haven't been watching TV (except for two episodes of anime per day) for more than a year now. We both feel we get more done, and that makes us happy. TV is the daddy of all timewasters.
This week, it is TV Turnoff Week! The tagline:
"Empowering people to take control of technology and not letting technology take control of them so they can live healthier lives."
And that is the way it should be. It's not just TV -- it's things like cellphones and email and IM as well. There are so many technological distractions, things that we pay attention to even if we don't want to. If we could shut those out, and use the technology on our own terms, we can lead more productive lives and be happier as a result.
(God, I sound like one of those NLP motivational gurus -- and I dislike that kind of talk. So just take it from me: turning off your TV will be the best thing you could do for yourself.) |
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| (no subject) |
[Apr. 9th, 2006|07:14 pm] |
A pox on the inventors of H.264 and Matroska and their unholy union -- especially since the same file recoded to XVid is actually smaller! |
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| More than meets the eye |
[Feb. 13th, 2006|09:16 pm] |
We all know that the Japanese are crazy about robots. We also know that the Japanese are even crazier about transforming robots. (Really, Shoji Kawamori has a lot to answer for!)
Well, it's here: a transforming robot, a car that can turn into a robot and back again! |
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| Always normalise your database tables! |
[Jan. 3rd, 2006|10:36 pm] |
When you design a database, you should always normalise your tables. I myself stop at 4NF, and this habit has served me well in all these years.
People might whine that normalised tables are 'harder to casually analyse'. That argument is nonsense. Sticky notes and printouts are for 'casual analysis' -- a database is for the cold, hard facts.
People might whine that joins are hard to do. These people need to teach themselves SQL in a hurry, and stop complaining. Lack of skill is no argument to do things in improper ways.
Yes, you will get more tables, and you will have to do some extra joins. But the advantages far outweigh the disadvantages:- Your domain analysis will, of course, be a little harder and take a little longer, but this is a good thing. It forces you to think the domain over, to check and double check with the domain experts -- and this ensures that you don't get any nasty surprises later on because you overlooked something.
- You don't duplicate data. This means that it is much easier to keep your data consistent. I think this is actually the most important advantage.
- Your data is stored 'atomically'. That is, a single object/concept occupies a row in a single table. This itself has it's own set of advantages:
- It is easier to create new relations between objects later on;
- You can change a single table independently of the rest of the tables, as long as you don't change any columns that are used in relations.
Modularity is a Good Thing, and this also applies to databases.
The main argument against normalisation is performance. Joins are expensive (in terms of CPU cycles), but not overly so. If you run a website or application where database performance becomes an issue, there are a few things you can do to speed things up:- Look at where you can add indexes (hint: the fields on which you join are prime candidates for that);
- Consider defining views or stored procedures for multi-join statements. These procedures and views are stored in 'compiled' form in the database, meaning that the execution plan is already in place by the time you do your query;
- If you need some data that can only be generated by an iterative process (which SQL is ill-suited for), then consider creating a table to hold this (non-normalised) data. A scheduled process could fill this table with data gained from the normalised tables. Of course, your application should never write data in this table: the data in the normalised tables is The Truth and therefore leading!
Normalising the tables in your database makes things so much easier. Trust me -- it always pays off in the long run! |
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| Internet governance |
[Nov. 15th, 2005|10:34 pm] |
Things are shaking up at the top of the internet food chain. The ICANN is under fire from several UN member states, who feel that a corporation under control of the US department of commerce should not call the shots on the world-wide internet.
Of course, people with strong opinions fall into two camps: those who wish to maintain the status quo and those who wish to see control over the root DNS servers relinquished to a UN organisation.
There are two arguments used by the proponents of the status quo: "If it works, don't fix it" and the freedom of speech argument.
It is true that so far, the internet has been working well. The tremendous growth of the internet in recent years has not provided lots of problems -- technically, there are no objections to the way the ICANN manages the servers.
However, as the internet gains more and more weight, as more and more business and government transactions are conducted over the internet, the internet becomes a vital part in the economic life of a country. The question is: do you want control over that crucial instrument in the hands of a foreign corporation that is under the control of a foreign governmental body? I can imagine that, out of principle, you do not want crucial infrastructure in the hands of a foreign government. The internet is much bigger than the US alone, and it would be good to establish a more neutral form of control.
The Galileo Positioning System is a good example of this: the EU finds that positioning systems are crucial to commercial and governmental interests, and thus can't tolerate that these resources are managed by a foreign government. Yes, it's expensive, but Washington won't be able to shut it down at will.
The proponents of the status quo object that a 'rule by committee', as a UN-instated internet governing body would undoubtedly be, would be too slow to adequately deal with the issues that will surface. I'm inclined to agree with them, but it is not entirely clear to me what issues demand immediate action (other than technical issues like server outages, but that's not the problem). Granted, generally speaking a corporation is much more efficient than a committee, but you must realise that the ICANN has a monopoly -- and the rules of the free market don't apply to a monopoly. In fact, it is precisely the inertia of the committee that could save us from a capricious corporation that wants to achieve goals that are not necessarily in everyone's best interest.
Then there is the free speech argument. It is telling that amongst the countries seeking to wrest control of the internet from the US are Iran and China -- countries whose governments aren't, shall we say, known for their love of freedom of expression. The internet provides means for dissidents to communicate with each other and the outside world -- vital for democracy. It is feared that the new governing body would be dominated by these undemocratic regimes, allowing them to impose their censorship over all of the internet.
This is indeed an important issue, one that is not to be taken lightly. However, in recent years the US has shown itself to be less and less concerned with civil rights. Who is to say that the US will not block future developments, like they did with the .xxx top level domain? National concerns dictate what the rest of the world can and can not do on the internet.
It might very well be the committee-inertia that saves us from these national considerations, if it comes to that.
In conclusion, I am not satisfied that the ICANN is the only and best way to govern the top level DNS servers. I would like to see more international control and a less US-centric view, but I am suspicious of the motives of the likes of China. |
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