For a number of reasons which will become evident over the next several weeks, I have started to do performance testing on the airplane.
My initial plan was to fly a performance test flight then make a change and then fly the performance test flight again and compare. It turns out there are just too many variables for that simple method.
Fortunately, there are non-profesional racers in the world who do this type of stuff all the time. They have been invaluable. The above image and description is based on their years of experience.
What is important to note is that the procedure strives to eliminate some variables, adjust for others, and mitigate still others.
The actual application of the procedure is a bit less precise than the description of the procedure. Here is an example:
I ran the above procedure three consecutive times in a single flight and yet the NTPS spreadsheet (National Test Pilots School) calculations yielded 157.8kts, 158.9kts and 160.1kts respectively. My hypothesis is that ground terrain was one factor I had not considered. The combination of trees, reflective poly covered tomato fields, and muddy inlets results in varrying amounts of thermal activity. The last of those three tests was performed completely over water and thereby significantly reducing the variability.
I plan to fly the test procedure over a couple more days in hopes to see the results stabilize. Once I have a trusted baseline, I can make the first change to the airplane.
It may all sound a bit boring but I'm actually finding the process to be enjoyable.
Don't expect to see me out on the race circuit as a result of this work. The airplane is an economy flier, not a speed daemon.
Anyone who knows me, knows I am not a performance driver ? at least no any more and not when there are four wheels involved. However, I picked up a used 2001 Merc 230 SLK back in 2003 and it is now an 8 year old. It is still in pretty good shape but will eventually need some TLC (Truck Load of Cash). So the question is ?
- Do I drive it until it breaks down or falls apart (accepting the diminished capabilities as time progresses) ?
- Do I keep it up as best as possible ?
- Do I attempt to improve it ? where I define ?improve? is to tune it for comfort, agility, and fuel economy ?
- Do I sell it ?
What is your vote ?
I did a bit of PHP coding this weekend (cue screams by programmers and a development managers everywhere). I liked Windows Live Writer the first time I ran it through it’s paces and now I like it even more. There is one serious caveat. The images that WLW creates and uploads are a bit “rich”. What I mean by that is they are bigger than they really need to be.
When I use GIMP and even Postie, I use a JPEG quality setting of 75. This seems to make reasonable small thumbnails for my blogs and even does a good job when the image is 575 px. On average, the 240px thumbnails are between 10kb and 20kb while the larger images are 50kb to 70kb. These sizes make it possible for readers using telephone modems and dial-up service to still have a chance to read the blog without falling asleep waiting for the page to load. I would like the pages to be even smaller but I use images in nearly every post so a typical page size is between 400kb and 500kb.
What I liked about WLW was that it took my basic images and create both a nice thumbnail with drop shadow effect and created all the necessary linking to the full size image. Postie did this too. The difference was I had to add the drop shadow to the big image and exaggerate it so that the thumbnail would have it when Postie scaled it down. Also, Postie make all thumbnails the same size and there was now way to control it on a post-by-post basis.
So, to get the control that I wanted I switched back to WLW but then I needed to find a fix for the larger that desirable image results. This is where that PHP comes in. I have created a crude but effective WordPress plug-in that detects JPEG files in uploaded posts and re-compresses them automatically. I even gave it a crude name “jpeg-quality75″.
You can download jpeg-quality75 here if you are interested. The install is very simple – unzip then upload jpeg-quality75.php to your WordPress plug-ins directory and activate it. It has not admin or settings.
The plug-in works by hooking the wp_handle_upload function in WordPress. This function is called for every file uploaded, the plug-in checks if the file type is a JPEG image and if so, locates the image, opens and re-compresses it using a quality setting of 75, and then stores the result back in the original location, overwriting the original. It leaves PNG and GIF files alone.
I’ll be checking it’s results for a few days but it seems to be doing a good job without corrupting my photos and graphics.
Doing sufficient backups, building virtual machines, and storing my transient video collection “on-line” requires storage, storage, and more storage. With three computers now getting sufficient backups to give me moderate peace of mind, I needed more storage than my RAID1 NAS (network addressable storage) was ready to serve. I had 2 750GB drives but RAID1 used those as mirrors so I only got the real capacity of one drive (and in reality, you never get 100% of a disk drive and so it was more like 700GB).
Today I added 2 more 750 GB drives. The system reconfigured itself for RAID5 so now I have 2 TB (yes, TB = terabytes). So, it should be a while before I run out of storage and more important, with RAID5 I have hot swappable storage – if any one disk drive should ever fail.
the down side now is there is no way I will ever have a fallback for the NAS. It has become a single point of failure if – unlikely as it may seem – the entire thing should bite the dust. (I truly hope that writing that was not asking for trouble.)
BTW: for those with slow-speed internet, I apologize for the 360KB image. I tried to make it smaller but it started at 2.7MB so I feel I did “OK” when all things are considered. For those asking “how”, all I can say is; “GIMP is one of the most amazing photo manipulation tools I have ever used – and I’ve used Photoshop and Photoshop Elements for years … and GIMP is free !
I have settled on using Ubuntu as my primary operating system on both my personal laptop and my work machine(s). There were
two three four driving forces behind the change.
First, I needed a non-Windows solution for my parents. Windows is just too susceptible to viruses, malware00% , spyware, adware, and Internet gunk. A Mac was not an option only because the nearest Apple store is 20 miles into the city and my parents don’t feel comfortable driving in the city any more.
Next, I needed more control over my work PC. I am 100% mobile these days which means I no longer have corporate IT to help me with things. That’s OK as I am pretty self sufficient. However, corporate still insists on their own version of what we have fondly come to know as corporate virus-ware. This is the stuff that “keeps your machine updated the way the company wants”. That’s all well and good until it either decided to reboot your machine while you are at a customer site, or insists you don’t have the corporate email or text messaging software installed and won’t let you use your machine until you install it. (It gets really funny when the IT helpdesk contacts you over instant messaging to help you with the fact the the virus-ware insists you don’t have instant messaging – but then insists you install it !) It turns out all of the automated virus-ware the company uses is Windows only. Since I can’t get them to buy me a Mac, and I am free to use Linux (because it means the company reduced its Windows headcount by 1) I chose Linux.
The third reason is that I have fiddled and twiddled enough with Ubuntu to make a user experience I really like and actually miss when I must use my Windows machines. Now, I realize it should not take fiddling, twiddling, and dittling. I also have been following the Ubuntu 7.10 release which has done a great job at incorporating all the things I really want. I’m holding off my mass migration until it releases in a few days.
The fourth factor is Linux is much more efficient and Windows has become bloated. I think a Pentium3 700Mhz laptop with 768MB and a 40GB disk should be find for running email, a browser, an a couple helper utilities. Windows has grown (along with all of the spy/mal/ad stuff) to be very slow. Ubuntu is very happy and zippy with that hardware.
Caveat: I wholly admit that Ubuntu is not everything I need. I will still have one or two programs running in VMware images. With VMWare Player and VMWare Converter being free tools, it makes it easy and fast to have an image or two for those rare occurrences each month.
I was talking to some people over the weekend that are still stricken with the dreaded “dial up”. It got me thinking about the performance of my blog again. I found a very helpful website for determining the bandwidth needed for a given web page – for instance my blog’s home page.
It turns out my blog’s start page averages about 200KB is size. Over the past few weeks it’s been as high as 225KB and as low as 180KB. I then looked as some blogs I enjoy reading. One has a current page of 525KB. Another is currently over 2MB.
Back to my blog for a moment, at 225KB, a person on a good 33.6 modem needs 78 seconds before the page is loaded. That does not include any network lags, rendering time, script execution, etc. I’ll be honest, if it took well over a minute to view a page, I’d probably give up. I hope my readers on dial-up are more patient than me !
The analysis recommends reducing the amount of HTML and definitely reducing the number of images. I could post with fewer images but as I already optimize the size of those images considerably, I’d rather not give up on them. The easiest way for me to do that is to reduce the number of posts. Currently, I show the past 6 posts. I could reduce that to 4 posts and list the next 4 older ones. On average, that would cut the size down by as much as 1/3 or about 60-75KB.
I’d be interested in how many posts make sense. What do you (the readers) think ?
By the way, if you are curious about sites you own or visit frequently, check out the web page analyzer at WebSiteOptimization.com