Last week I gave a long overdue presentation on my experiences at Radar Networks where we attempted to built a consumer product using Semantic technologies. I presented this at the San Francisco Semantic Web Meetup that was hosted at my old company CNET (now owned by CBS).
I don’t work in this space anymore but I wanted to share the experiences that I had in the two years I worked with the Semantic Web. This is a very engineering-centric presentation based around the idea of engineering web-scale systems. Hopefully it comes in handy for some of you out there interested in this slowly growing space.
Its 2010 and there still isn’t an ad-free and non-paid way to have many-to-many text messages with a group of people! Almost a year ago I built a script in PHP that leveraged twitter as the middle man to solve this simple problem for my neighborhood buddies; essentially creating a mobile chat room. Just last weekend a few of my industry friends and I decided to sit down and productize the thing as an exersize. Two days, some pizza, and a bit of open source code we had Twitmob.com. Here’s how it works.
Simply create a Twitter account for your group, say @bffs_4_eva, and invite your friends to follow. Then when a follower tweets “@bbfs_4_eva happy hour!”, Twitmob will re-tweet the message. Now all of your other followers will see, “RT @a_follower: happy hour today!”. Once your friends turn on Twitter’s mobile updates for the group you can chat with them anywhere. No smart phone required!
Check out Twitmob.com to see how it works. Its quite simple and only takes a few minutes.
In years past I have camped in a tent under a large shade structure with the rest of my camp mates which is all fine and well but this year I wanted to try something different and a little more comfortable. The yurt will still fit under the shade structure it’ll just keep me that much cooler.
A hexayurt has many advantages over a traditional nylon tent. The main one being insulation, as that is what it is made out of. Not only will it slow down the transfer of heat it will also cut down on some of the noise, mostly treble. The other advantage is dust prevention. As this is sealed with wide bi-filament tape at every seam and taped down to a tarp dust has a hard time getting in.
Above you can see a rendering of what my yurt looks like. I used 8 panels of 1″ thick Thermax, sometimes called R Max, rigid foam board insulation. I then bought 2 rolls of 3M 8959 6″ wide filament tape from goodbuyguys.com (link) to tape up all the panels edges as well as connect them to each other. Below you can see a model that someone had built. I built the same model which made the actual build a lot easier.
As you can see, this is a folding hexayurt. This makes assembly out in the desert very simple and less time consuming. Doing more work ahead of time makes this simple setup possible. Grab a friend and in 3 or 4 hours and you can have one of these built and ready for transport. Oh, and I found that cutting the foam with a circular saw made the cuts more precise and go a lot faster. Below you can see a photo of it completed and unfolding. It really goes up quite quickly.
The only other things you have to worry about are anchoring it to the ground and ventilation. To anchor it to the ground I ran two long strips of tape across the broad side of the structure, giving 4 anchor points on each side. Then I ran a rope down the ridgeline. This should be sufficient enough anchoring. Once out on the playa and anchored to the ground I will tape the yurt to the tarp to seal out the dust.
Regarding the ventilation I have a couple of ideas but unfortunately I am unable to give them a good test given the San Francisco climate. My current plan is to use two $25 attic fans that are solar powered. I’ll report more information once I return from the desert
For more information check out hexayurt.com. And finally, the best part of this design is the entire yurt folds down to be a little over a foot thick and only 4′ x 8′ so it can be transported on top of a car.
Its been nearly 6 months since my new gig as a lead engineer at Transpond and I havent posted anything about software or much of anything else for that matter. I’ve been busy with many other projects as well as learning and writing PHP. Well, mostly writing as the learning curve isnt bad at all. The more I was able to block Java and what I know of it out of my mind the faster I was able to learn PHP.
Anyway, there are tons of books and blog posts about how to write PHP so Im not going to go into that. What I have compiled though is a list of things that helped me get over the hump. Although Java and PHP have a lot of similarities, their life cycles are different. Here are the things the differences that stood out the most in my mind.
Classes
Now that PHP is fully object oriented we can use classes as well as objects. Lots of new open source projects out there seem to take advantage of them; however, a lot do not, especially older ones. What I find to be very common throughout PHP are the untyped array objects with lots of nested arrays. This appears to be very standard. The sooner you get over this fact the sooner you will be able to code. The point of a dynamic language is to be able to build quickly and not deal with POJO’s.
Instantiation
Just like Java, classes in PHP have constructors and even destructors; however, they are not declared as you may think. You will need to use the special notation for these functions, __construct and __destruct respectively. Also, be careful when building more complicated stacks or frameworks. Objects get destructed at unusual points in a requests lifecycle so getting your debugger running can come in handy.
What is also interesting is that classes cannot be static in the way we would normally think about them. You can make a class that has all static methods which effectively makes a class static but you cannot use the static keyword for a class declaration.
Imports (require or include in PHP terms)
Unlike Java, PHP is file based not package based. This makes for some interesting issues at first. Trying to grok this idea and deal with file paths can be daunting. What we found to be helpful was name spacing which is somewhat recent to PHP. We use that in conjunction with __autoload() which makes class loading very simple. Essentially we can dynamically load classes easily based on their namespaces and not their file location as much (our autoloader handles that).
Methods, functions, and void (or lack thereof)
As you probably already noticed, methods are called functions. These function do not need to declare what type of object they will return, as this is a dynamic language. In fact, the same method could return nothing (void), and object, or a string. This puts the burden of good engineering on the caller.
Functions in PHP (methods in Java) are however similar in the way they are declared. They can have public, private, and protected declarations, as well as static, abstract, and final keywords. This makes the transition from Java pretty simple, however; there is something strange I noticed. Member variables cannot have the final declaration which I find to be frustrating but there are obvious ways around it. The main reason for this being, most objects are passed by value so modifying a member variable is harder than in Java. I will go into this more later.
Conclusions
So far I am really enjoying PHP. The environment is very simple and straightforward, there is a ton of support for it, and there is a plethora of open source projects to choose from. All of this makes for a quick development time and a quick ramp up time. As I mentioned before, the sooner I stopped thinking about how Java worked, the sooner I was about to pickup PHP.
Every shop needs a good workbench and its about time I built myself one. I sourced most of the parts locally from the $75 solid maple butcher block top to the $40 shelves with drawers I got at a local salvage yard. The only things I bought new were the three Rockler vises which I have yet to install. The picture above is of everything all mocked up.
I have assembled the bottom section out of 4×4′s and 2×4′s secured with long galvanized deck screws. The base frame itself is 45″ long and 23″ deep. The butcher block will overhang 3″ on the front and back, and 12″ and 18″ respectively on the left and right. This will accommodate the vice setup I will be installing but I will post more on that when its complete. For now, you can see more pictures by clicking on the image above.
Since I returned home from Burning Man I have been extremely busy with a new job and a lot of new changes in life so I have not been able to post any updates. Now that I have finally come up for air, here are some pictures of the final product. Check out the Flintstones art car photo set on Flickr.
With Burning Man less than two weeks away my buddy Aaron and I are getting close to completion. All the finish work adds up but its the most exciting part. All the details are what makes this car authentic. Just recently Aaron finished rounding and staining the canopy supports and I finished rewiring the thing. All the seats are now upholstered and I just finished painting on the faux stone on the car.
In the picture above you can see that we now working the side logs what I think we have figured out. Below you can see all the switches and lights. We hollowed out bones to cover the switches and shells cover the indicators but glow at night.
This week my father flew to San Francisco to help me, and teach me, to build a banister and repair a staircase. We tore down the wall that used to be there, replaced all the treads, and put in a matching banister and railing that we copied from the upstairs banister. For the past five days of the build I have been blogging over on SanFranVic.com where you can follow the story and see all the photos.
Since space is always at a premium, especially in my kitchen, its important to use every inch as best as possible. Instead of having two separate trash bins it made more sense to combine them into one piece of furniture and gain table top space. So I searched the internet to find something that would fit but unfortunately nothing came up. So it was off to the shop to solve the problem.
With the help of my roommate, we built this trash and recycling center out of maple plywood using simple dowel joinery. We finished it in a cabernet color and added some simple hardware like magnetic latches and handles from our local hardware store. All in all the project only took a few hours total and solved a big problem.
My long time friend Caroline and her fiance Regan asked my housemate Brian and I to do the lighting for their wedding because they had seen our renovation work on sanfranvic.com. We were both honored and excited to help out. Not only did it save them thousands of dollars from hiring a lighting expert it allowed us to give them something they will always remember.
The light array was pretty simple and only took a few hours to setup. We hung up five strands of 32 foot strings of ping pong ball lights from the reception house to a rope 10 feet up that we ran parallel to the house. That rope was held up by two pieces of 10′ galvanized steel conduit that was anchored to the ground with a few pieces of rope and some stakes. The hard part was just getting the lights up and taught so they were high above everyones head. I’m happy to say that even after the storm that came through they still stayed up and everything went off without a hitch.
I’d like to thank Caroline and Regan for having me and I was honored to be a part of your wedding. I was happy to help and even happier to give you a present that you’ll always remember and cant be returned. It was a great time and something I wont soon forget.
