I work with atomic force microscopes (AFM’s). At their heart is a PID control system that keeps the probe doing the right thing, and giving us ultra high resolution images of a variety of things (topography, elasticity, etc). But I realized that I knew little about actual control systems. I was not an engineering student in university, so I wasn’t exposed to the concepts.
Now I am diving in. Fortunately, there is a ton of great information on the web about the theory and practice of control systems, so that is cool. However, it is clear that my physics degree, while heavily laden with mathematics, was deficient in discrete mathematics. In physics, in general, you look for closed form solutions. Thus you are integrating and differentiating continuous functions to get to a solution. Mostly, you don’t care about numbers and numerical values. That is something that a calculator can give you with the equation you generate.
However, engineers deal with concrete things. Forces, lever ratios, stasis, and most importantly actual real world values for their problems. As such, they use a lot of mathematical modeling, and computers to simulate results. Hence, the use of discrete mathematics instead of continuum mathematics.
Of course, I took numerical analysis, and numerical methods for physics, and have hacked around enough in Matlab to know some of the basics, but I got that information empirically, not from first principals.
In in effort to save money, I was investigating options to reduce the cost of my monthly cell phone bill. I had actually considered cancelling it, but thought better of that, since I use it for several 2-factor authentication sites.
So I head over to AT&T’s site, log in, and start the “upgrade” process. I figure I will just get a cheap feature phone, and be done with it.
There are only 4 choices, 3 of which are web only (and sold out), so my only choice is a $200.00 Samsung flip phone. Merde.
(For all those that say cancel AT&T and go with a PAYGO carrier, I can’t as I do a fair amount of traveling, and I need a phone that will work in Europe and Asia.)
So, for now I keep my iPhone, and my data plan and suck it up.
On the way home today, I saw a truck hauling a piece of motorcycling history. A Honda V65 Magna, circa 1983, was strapped to the trailer. One of the first Honda V4’s, the v65 was the boss bike that year. It was the fastest off the line, and held the production quarter mile title. Shaft drive, 65 cubic inches displacement, and a laid back cruiser styling.
The Honda Magna V65, king of the hill in 1983.
It was pretty rough, but I strongly suspect that they were going to restore it. For a 30 year old bike, it seemed to have a lot of promise. I hope I see it on the road sometime.
I remember wanting one of them bad. I recall that the early versions of the V4 had some reliability issues, but that wouldn’t have deterred me. Of course, the last thing an 18 year old male with hormones raging was a bike capable of sub 11 second quarter mile times.
Dover Publications, also known as dover press. I first became aware of Dover when I was in college. Dover picked up the rights of old text books that had gone out of print, and packaged them as reasonable priced paperbacks. Since I studied physics, and much of the core material was pretty static (not the modern, high energy, or particle physics that were evolving rapidly, but mechanics, field theory, E&M, and others were quite relevant. Textbooks that had gone out of favor were often packaged for sale at very reasonable prices, as low as $6 up to the mid $20’s. Text books that if were being used would cost (even in the 1980’s) $40 – $100.
While I bought my required texts, I also picked up others on the same subject to give me additional points of view on topics. I primarily bought mathematics and physics texts.
Recently, I have found the need to brush up on some basic topics. The products I work on use PID digital controls. So I started looking for digital control books. Amazon had several, but they were current text books (read: $100 or more). Ouch. Hit dover’s website, and I find dozens of texts for less than $15 each. I pick one up.
When reviewing it, I realize I need to expand my knowledge of discrete mathematics, again, Dover to the rescue. A classic under grad text (and a companion volume on topology) are on the way to my house. Total cost $27.95.
Back in university, the internet wasn’t even on the horizon, so I would make the trek to Cody’s in Berkeley. They had a huge selection, ready to be exchanged for my hard earned cash. But today, it is a lot easier, you can buy them online, and browse their entire catalog.
Dover does have a lot more than just geeky science and physics books. There are books for all ages, and of a myriad of topics. I highly recommend a visit to their site.
Since I don’t have kids, I don’t know why this has happened. From a very early age (1st grade) I walked to school. We lived probably a mile, maybe a little less, but a group of us neighbor kids would gather and stroll to classes every day. Probably by the 4th grade, I graduated to bicycling to school (I remember my cherry Schwinn Stingray being stolen, and being distraught over it). By high school, I was walking or cycling probably 2.5 miles to school, and there were some kids who came in by bus. Unless it was raining really hard, we didn’t get a ride from one of the parents.
But that is not how it works today. There are still buses, and there is a stop near my house, I see high school aged kids get on at 6:50AM. But I also live about 2 blocks from an elementary school. They have actually re-configured the street to accommodate the long line of cars to drop kids off. After school, there is a queue to pick up kids that extends about 3 blocks (and it is hugely disruptive).
What changed?
Serious question. I don’t think the streets are any less dangerous (and we has cross walk guardians when I was in grade school, some 40 years ago). I believe that the rate of stranger abductions is about constant (although there is a lot more media coverage that sensationalizes the cases). Are there fewer buses to carry kids who are too far to walk to school? Or is it just expected that helicopter mom’s will be driving little Suzy to class every day? If anything, the idiocy that I see with the parents trying to beat a red light (and wait one more cycle) to get little Johnny to class is more dangerous that walking.
I learned very early on some simple rules. Memorize your address. Know your phone number. Don’t accept rides from strangers. Strangers offering free {candy|ice cream|toys} are to be avoided at all cost. Never be afraid to approach an adult and ask for help. Cross only in crosswalks, and when the lights permit it. Know the rules of the road (when bicycling) and ride safe.
One thing that I will say, many of the kids I see being dropped off could use the exercise of walking to school.
There are many valid reasons to hate GoDaddy web hosting, from their soft-porn advertisements, to their owner’s proclivity to go big game hunting in Africa, to the barrage of pushy marketing of their goods and services (no, I don’t want to add domains today). Today though, I will be complaining about their support and their absolutely shitty hosting platform.
Until Friday, March 22, 2013, the few times I needed support, I received quick, accurate, and insightful help. Leading up to the Friday a website that I run for a local non-profit, Southern Arizona Greyhound Adoption, had been sluggish in loading for a week or so. I noticed it taking a minute to respond to the original URL request. and similarly on the back end (we had a fundraising event on Wednesday, so I was doing daily tweaks to keep the excitement up) it was a pig, taking minutes to load.
But starting Friday morning, it was pretty much unreachable. It would time out, or present the default Apache 500 series error. I could ping the server, I could FTP to it, I could SSH to it, but the Apache/MySql system seemed completely broken. I head on over to the support area, and log a ticket. They estimated that it would take 11 hours to get a response (in the past it had always been less than 2 hours), and the status noted that Friday Evening they would be doing maintenance on their 4GH platform (where my linux hosting is) to fix some resource allocation issues. But no real details.
I also went to their customer forums, and noted that there was a long stream of other people with similar comments/complaints. I posted there as well, and got a prompt response from one of their support droids, telling me that the upgrade/maintenance to the 4GH platform will resolve the issue. But also 4 other people commented on my post that they were experiencing the exact same thing.
Groan.
Saturday morning, and things are back up, but still sluggish. Feels like there is some delays in their system. 20 hours after opening the ticket, I get an email response. Instead of mentioning anything at all about their problems, I get a list of unhelpful suggestions:
Support Staff Response
Dear Geoffrey,Thank you for contacting Online Support. You can make modifications to your site that improve performance. Some of these changes are easy to manage while others might take some time to figure out.
Here are four things you can do to speed up your site:
GZIP Compression
Smaller pages load faster, regardless of your Internet connection speed. You can make your pages smaller by compressing them with GZIP. (GZIP is only available on our Linux Hosting plans.) For more information about GZIP and our hosting, see Compressing Web Pages for Faster Load Times.
Image Sizes
If you use HTML to make large images small, a site visitor still needs to download the larger version. If you need a small image, don’t use HTML to do it—shrink it in an image-editing program instead.
Scripting
You can edit to say more with less. A good programmer does the same thing with code. If the code on your site is inefficient, it impacts your site’s performance. There isn’t a quick fix for bloated code, but if you’re using GZIP and you’ve reduced your image sizes, analyze your code to make your site even faster. One way to make a database-driven site faster is to use a database index to improve the speed of data retrieval.
CSS
Cascading style sheets are great for formatting the look and feel of your website. If your style sheet contains a lot of styles that aren’t being used, you are forcing browsers to download things they don’t need. If you’re trying to maximize performance, trim your CSS files and remove anything that’s unnecessary.
Please let us know if we can assist you in any other way.
For the record, GZIP compression was enabled, I run the site on Joomla, I make sure that all the images are 640 pixels wide or less (and set thumbnails to 200×200 pixel png’s for speed), and really? want me to rewrite the Joomla core to use less PHP scripting? I already have a pretty clean CSS.
So basically, they flipped me the bird, told me that the problem was mine, not theirs, and closed the case. Oh, and in the header of the email they were trying to sell me more domains.
Fucktards. I am now preparing to move the site and domains to my personal hosting provider, the awesome folks over at Media Temple. I will abandon a year of prepaid Go Daddy hosting to get away from those scumbags.
I finally took the plunge and got my reloading press setup again. It had been sitting idle on my workbench, partially disassembled from the move, and generally looking sad. But now it is back together, and when I get about a 2′ x 2′ piece of plywood to reinforce my workbench, I will bolt it down and then get back to reloading.
I also cleaned all my firearms. A couple had been put away dirty from the last trip to the range, so it was time.
I also need to find a good range here in the Chandler/Gilbert area so that I can see if I still can shoot.
A recent post I mentioned that I would follow up with my irritation with Arizona cyclists. In that post I mentioned the insane practice that is widespread of cycling on the sidewalks, that greatly increases the hazards to people walking.
Today, I am going to grumble about cyclists who are unfamiliar with the rules of the road.
First, I grew up in California, at a time when the schools were well funded (that is, before Proposition 13), and we all learned to use hand signals properly. Just like in a car, you use your left arm to signal intent. Up for right turn,straight out for left turn, and down for stop. Easy peasy, except here in Arizona, people seem to use their right arms to signal right turns, their left arm to signal left turns, and some other hand-wavy things that make no sense.
Second, I continue to see cyclists completely ignore stop signs. As a cyclist, I sometimes slow to an “almost” stop, then move on, and I feel bad about that. But here, I see cyclists not even making an effort to stop. They look to whether there is cross traffic, make the decision to just blow through it, and do it. Crazy.
And you wonder why many car drivers get pissed off at cyclists.
Well, I have been an on and off user of posterous for a few years. Probably less than 100 posts, some insightful, some silly. I guess they will fit here.
