Monthly Archives: April 2005


Pdftk manual

Or as the site itself calls it, ‘Man Page’

I get occasional hits at my site looking for ‘pdftk manual’, so I figure as a public service I’ll give a direct link here. I’ll also ask Sid Steward over there to add the word ‘manual’ to his page so he can draw the hits directly :-).


Google does not own the bleedin’ web!

A bit of a rant here…

I have seen a number of instances around the web now of the reasoning “so-and-so published such-and-such on their web site, therefore, they’ve violated Google’s Terms of Service”. In one instance, a web host (one I don’t think is a subsidiary of Google) went as far as saying “so-and-so published such-and-such on their web site, therefore, they’ve violated Google’s Terms of Service, therefore they’ve violated our Terms of Service”.

WHAT are you talking about?! As much as I dig Google and all their crazy services, they do not own the web.
Firstly, show me where in Google’s Terms of Service there is any mention of what someone may or may not put in the content of their web site.
Secondly, by what legal binding mechanism has a random web publisher been bound to follow ANY of Google’s Terms of Service or other wishes? Publishing something on one’s own webspace and having Google crawl it, because they chose to, does not constitute a legal agreement.
Thirdly, there is no thirdly. Though if there was, it would be something about how even if people are deliberately trying to manipulate Google or other search engines, they’re not committing any crime deeper than possibly being overzealous about their particular message.
(Fourthly is a great song by King Missile. It is also the point that why would an organization declare that “Google’s rules, whatever they may be and whether we understand them or not, are our rules”?)

The point of my rant here is not that I think there’s any legal meaning to these weird articulations people make, but that the thinking behind them indicates a sort of insidious self-delusion about power relationships that eventually petrifies itself into actual existence. And given that I own your mind (check my Terms of Service), I order you to not be prey to such delusions.


Alpha shapes

Since Darrin Lemmer is stealing my Google juice with his posting of an email I sent to him :-), I’m going to post about that topic here.

Alpha shapes are this pretty cool geometric formalism that can help make sense out of point clouds. I came to them in investigating a nice way to render tri-dexel structures, but that’s a topic for some other time.

The simplest definition I’ve read is that alpha shapes are a generalization of convex hulls, in that they give a tunable parameter which, when set to infinity, produces a convex hull, but when set smaller produces a cell complex that more closely wraps the point set. At its best, subject to a couple of conditions that hold in useful cases, the wrapping is ‘perfect’. Anyway, I’ll let some others explain it, as I haven’t the patience right now, and I do have the links:

The idea behind alpha shapes is explained pretty well on this page, with a nice little Java applet that helps give you an intuitive understanding of it: alpha shape applet.

The implementation I used to play with this some is by Clarkson, at Bell Labs. Note that what this really implements should probably be called ‘alpha solids’. That’s alpha shapes with the interior simplexes removed. That’s generally what you want, but it’s something to be aware of as a difference from other implementations and from the uses of the term in the literature. You’ll probably want to use the ‘-A’ option when playing around to learn what it does; later you may want to use the ‘-aa’ option; in either case don’t forget to use ‘-mxxx’.

This is the alpha shapes page from one of the guys who first wrote up the idea, Ernst Mucke. There’s some (binary) code linked from there too, which is fun to play with but can’t be integrated into your own code without getting the source from them.

There used to be a page at but I don’t know where it is now. It seems to come and go.

The CGAL library has an alpha shapes implementation that might be more suited to use within an application than the Clarkson code, although it doesn’t seem to do the alpha solids thing, and it has a separate commercial license (but free and OS for non-commercial use).


NREL Biomass Research

Just had to put in a bit of a plug for NREL. Very cool stuff going on there, much of which will be vastly more important than you may realize…

It was fun to take a poke around the place with my brother-in-law who works there. We primarily looked at stuff related to this: NREL: Biomass Research – Biochemical Conversion Technologies – Projects


Seeing What’s Next

I just read “Seeing What’s Next” by Clayton M. Christensen, Scott D. Anthony, Erik A. Roth. (LOC, Amazon)

I’m gonna have to come back to this one a few times, and maybe check out the authors’ other books.

This book covered a serious hole in my informal (and my short formal) economic education. As absolutely important as innovation is in the grand economic scheme, I hadn’t yet read anyone trying to put a formal framework around it. Of course, there’s always going to be that ineffable core in the process that gives us a reason to call it ‘innovation’ rather than ‘just what one would expect’, but there are meaningful things to be said about how a innovation is accepted into a market or markets, and ways to predict who will take greatest advantage of the innovation in a business sense. That’s what this book addresses, and from my first read through it, it seems like the theories presented and their applications have some solidity.

The fact that my economic education is rather limited didn’t seem to be much of a hindrance to my reading this book; the ideas are presented in a way that doesn’t require much there. I’m sure the combination of these ideas with a more complete understanding of economics would be more powerful.

I haven’t yet tried to take their theories and apply them to something on my own, and I don’t necessarily feel like that’s going to be easy without their extensive experience and/or the benefit of hindsight. And of course, a theory isn’t much of a theory if it can’t work beyond those boundaries. But it’s far too early to tell whether there’s a lack in the book or in me that’s at the heart of my uncertainty there.

In any case, I think this is a great read in that I gained a bit of a foothold in understanding some of the most important and complex economic events out there, not to mention a couple concrete ideas about where to place some of my intellectual effort in the near future.


Liquid lens

This kind of stuff is really cool. Not only is it a potential revolution for camera optics, and especially for cell phone camera optics, but it’s also got a bit of biomimicry, and it’s clearly ‘out of the box’ thinking relative to standard mechanical optics: Smile, You’re on Liquid Camera


Forests Forever

It may be an ad for Fujifilm, it may easily exceed the RDA for Flash, but it is pretty neat: Forests Forever.


Solar Electric Light Fund

The Solar Electric Light Fund sounds like a great thing. The combination of green technology and the strategy of working at a small scale to get into places where large scale operations wouldn’t make economic sense has a lot of power.

It’s really fascinating, this world…


New rechargable battery

Rock on, Toshiba.


Wireless network ‘conduit’

Since I’m too lazy to try to find such a product, and not motivated enough to create and market it if it doesn’t already exist, I’ll just describe this thing, float the description gently on the ether, and maybe by the time I need one, it will materialize for me. By the way, if you find yourself motivated enough to market it, you could give me the motivation to create it by consulting with me to do so. You take the risk, I provide the skills :-).

I am in the early stages of getting ready to buy a house. I will need a whole-house network. I will not want to make this network wireless because I don’t feel confident in the security, I’d like to reduce spurious radiation if possible, and I want the speed and reliability of wired LAN that wireless just doesn’t seem to match.

On the other hand, I may not want to bore holes in ceilings and floors to run conduit, should it not be in place already. But, it seems to me that a purpose-tuned application of wirless network technology could be used to patch across the gap, while simultaneously avoiding the (perceived) shortcomings of wirless. Given that the stations are fixed and close to one another, highly directional antennas with just-enough power could be used to increase security and reduce radiation. That the stations don’t have to talk to anyone but their single partner gives some potential advantages in security, speed and ease of installation.