Justin Curry has written an excellent introduction to cosheaves. Cosheaves are the dual notion to sheaves, but many specific properties of sheaves of sets do not dualize, so they have a somewhat different flavor. The introduction includes some applications of cosheaves in networks.
Simon Willerton has thoughts on PERT charts as copresheaves.
do you realize that the title to your blog has been taken over by some type of spam-bot? it’s the craziest thing i’ve ever seen.
What are you seeing, exactly? I’m not seeing anything wrong, but I could be missing it. There has been a lot of gibberish spam in the comment section lately.
I’ve seen it in your RSS Feed (the spam title). It looks like a plugin switched to the dark side or your admin account got compromised. There has been some buzz about a bot trying to get into wordpress installations, so you might want to spend some minutes reading about possible wp security issues.
Thanks! Someone emailed me that they ran across my article because of your post. Glad to hear that people are benefiting from it (even if it is way too long).
Konrad, I think I fixed it. There was a PHP vulnerability that allowed someone slip code into the WordPress installation. I think the real goal was to slip a bunch of links to GoogleBot, to raise the PageRank of pages, which is why it only showed up in certain circumstances.
Justin, my pleasure. It’s good to get evidence that someone other than spambots read the blog.