Christian Dunn’s Web Log

This is the season when lights are placed upon trees, buildings, and other structures in celebration of Christmas and other holidays. Most people are used to seeing these lovely displays of lights during this time of year. This year, however, there’s something different about many of the lights that you may be seeing. Because LED (light emitting diode) technology is becoming increasingly popular, this year, many of the Christmas lights that are up this year are strings of LEDs.

What are LEDs?

Simply put, a diode is a component of integrated circuits that allows electricity to flow in only one direction. A light emitting diode is a diode that contains chemicals that emit light when a current flows through it.

What are the advantages of using LEDs as holiday lighting?

LEDs have many advantages over the traditional incandescent bulbs when they are used as Christmas lights (as well as for many other lighting applications). They use substantially less energy than incandescent lights do and they often produce more light at the same time - they are brighter.

Because LEDs are efficient, they do not get hot when they are lit because very little of the energy that powers an LED is converted into heat. Also, their efficiency allows them to be more environmentally friendly. Finally, as opposed to incandescent lights which emit light of approximately the same color (warm white), LEDs can be designed to natively produce a variety of different colors.

What are the disadvantages of using LEDs as holiday lighting?

Although LEDs offer many advantages over incandescent bulbs for lighting, there are still a few caveats to using LEDs for holiday displays. Because the technology for LED lighting is new, strands of LED lights tend to be more expensive than strands of traditional lights. However, this up-front cost can be defrayed by the energy savings that come from using less electricity to power the LED lights. Some strands of LED lights produce a stroboscopic effect when they are lit - that is, they flicker - and that might not be acceptable to everyone, but generally the higher quality strands of LEDs do not appear to flicker.

Understandably, some people would prefer to continue to use the traditional type of lighting for decorations. Most strands of LEDs on the market today do not produce the same colors that the incandescent lights do.

Conclusion

LED lights offer brilliance, energy efficiency, and high-tech festive flair to Christmas or other holiday decorating, but they may not be appropriate when a more traditional ambiance is desired.

Coming Soon

The state capitol building of the state of Vermont has trees in front of it that are adorned with gold colored LED lights. The state has elected to decorate with style and energy-efficiency. Pictures coming soon.

I heard about this today in my physics class, it’s called Sierpinski’s Triangle, and there is an easy way to make this impressive looking figure. It’s called the “Chaos Game.”

Sierpinski

The chaos game works like this: First, draw three points, which will become the three points of the largest outside triangle. Assign a value to each of the points so that you will be able to pick them with any sort of random number generator, like dice or a ‘random’ number procedure on a computer. Now, draw a point anywhere inside the triangle, and randomly select one of the three points on the triangle. Draw a line between your first point, and the selected point on the triangle, and then draw another point half way between the two points on the line. Repeat this process for many more iterations, with each iteration starting from the point that you last drew, and Sierpinski’s Triangle will be formed.

After about 100 points drawn, the shape begins to take form. As more points are drawn, the figure becomes clearer. I don’t suggest doing this by hand, though. It’s much faster with the use of a computer program.

I wanted to see a program draw the triangle, so I decided to write one. The source code is really quite simple, and I used the Allegro game programming library to make adding the graphics easy. If you’d like to download the program, along with the source code (and necessary libraries), please click here.

Project Euler

I have recently been introduced to Project Euler. At www.projecteuler.net, Project Euler provides a large assortment of problems that require the use of mathematics to solve. However, what makes the Euler problems different than many other math problems is that they are designed to be solvable with the help of a computer.

The first Euler Problem that I solved, because it was presented to me by a friend in C Programming class, is Euler problem number 205. It reads like this:

Peter has nine four-sided (pyramidal) dice, each with faces numbered 1, 2, 3, 4.
Colin has six six-sided (cubic) dice, each with faces numbered 1, 2, 3, 4, 5, 6.

Peter and Colin roll their dice and compare totals: the highest total wins. The result is a draw if the totals are equal.

What is the probability that Pyramidal Pete beats Cubic Colin? Give your answer rounded to seven decimal places in the form 0.abcdefg

The program that I wrote to solve this problem can be found here. I’m not going to post the answer to the problem here, however, because that would spoil the fun.

Euler Problem 205 Solver Program

iTunes Version 8.0 has been released! Version 7 has been around since September 12th, 2006! That’s two years as of today. I was pleasantly surprised to learn of this great news, which was announced along with e-mails about the new iPod Touch and iPod Nano. My iPod Touch is still working well, so I have no intention of buying a new iPod, but I rushed to download iTunes 8. Here are some of the things that I found:

Playlist Generator (the “Genius”)

The Genius playlist generator uses a massive database of information about songs in your library, so that you can choose any song, and if there is enough information about it and similar songs in your library, the Genius will make a playlist of music complementary to your song choice. The iTunes Genius requires an iTunes account to function, because it takes information about your music and compares it to its own information on Apple servers.

The New Visualizer

The psychedelic new iTunes visualizer, as pictured here, looks great. It looks like it’s in space, with modern lighting effects and 3D animations. However, if you prefer the classic iTunes visualizer, that is still available for use also in iTunes 8.0.

For use with Windows Vista Business and Windows Vista Ultimate editions:

Go to the start menu
Type and launch “Local Security Policy”
Click “Local Policy” then
Click “Security options”
Scroll down until you see policies related to the UAC (user account control).

Double click on the policy that says “User Account Control: Behavior of the elevation prompt for administrators in Admin Approval Mode.” A dialog box should open up.

If you want to make it so that you have to enter a password to elevate a program to administrative levels, select “Prompt for Credentials” and click OK. That way, if you want to be a nice person and let people use your computer sometimes but also don’t want them to change settings and programs or run a standard user account you can have that level of password protected security. It works even better with a fingerprint reader!

UAC Password Protected

This has advantages, therefore, for a computer that might end up in the wrong hands.  Another advantage of password protecting the UAC prompt is that it prevents malware from clicking “OK” for you if you choose to not have the UAC pop up with the black background. The black background behind UAC prompts that appears by default represents the secure desktop that the UAC is in, secure meaning no other programs can get at it and manipulate it. Only the user can do that. Many people find that black background annoying though, and disable it. Disabling it means that programs can move the mouse and the keyboard and that could allow a malicious program to click right by UAC prompts and elevate other malicious programs to administrative privileges! Password protection, however, makes that very unlikely, as a malicious program would have to know your password to automatically click and type through UAC prompts. That way, you can have UAC without the annoying blackout screen but with an added layer of security!

Though the download wasn’t working on July 11th for the iPod Touch, surely enough on July 12th it was working, and since then I have installed the new version 2.0 software on my iPod. It works well, with only the occasional crash that reboots the device caused by some applications. It is worth the $9.99 upgrade, as the new firmware not only allows for custom apps but also for improvements to the core software.

The apps, however, have so far turned out to be not particularly exciting. There are some fun games (for a cost) such as Bejeweled 2, Crash Bandicoot, and maybe Super Monkey Ball (I have not played any of these though). For useful apps though, not very many are to be found on the App store. The app I’ve made the most use of is “FiatLux,” which simply displays blank colored screens on the iPod’s large touch screen so that it can be used as a sort of flashlight. It makes a great reading lamp.

The iPod has unrivaled aesthetic and entertainment value for a portable device, but it still doesn’t match the utilitarian advantages of Windows Mobile. That’s fine. Though, it is also inconvenient that the apps are so tightly controlled by the App store. If you want to write your own iPhone/iPod Touch apps, you need to do so with the iPhone SDK and it can be distributed only through iTunes.

For me these are only inconveniences. All in all, the iPod Touch 2.0 upgrade is yet another quality software update for one of the coolest portable devices yet released.

I started taking driver’s education today. My goal in taking it is to drive well, learn the rules of the road, and earn my junior operator’s driver’s license by the end of summer vacation. That way, I will be able to drive my own vehicle for my 12th grade year.

First of all, what I’m about to say here does not make the UAC less annoying. If you want to disable the UAC and get rid of the security prompts, it’s pretty easy to do so.

Regardless of popular discord with the Vista User Account Control, I find it to be somewhat useful, even for advanced use. If you know what are you doing with your computer, it still is helpful to have a protective shield against all programs that seek administrative access. In fact, it seems to me like the UAC is more useful for tech savvy users who know what each UAC prompt means than for those who don’t always understand exactly what it is that the UAC asks. The UAC allows the computer administrator to know more about what is running on their machine.

There’s one problem I’ve found. This doesn’t apply to everyone either, but it applied to me. On my computer, I had one active administrative user account. Whenever I would let anyone else use my computer, I felt protective of the machine because they had full access. If they wanted to run an administrative task, something that would change my computer, a simple click of a button would allow that. I wanted to make it so that I, or anyone else who might use my computer, would have to enter a password before running any administrative tasks. This would make it so that when someone else used my computer, or when I left the machine running, I could feel more secure about it because anyone other than myself using the machine would have only standard access to it.

I’ve heard that this kind of setup is similar to that which is found in Linux machines. I’m not much of a Linux user, though I have tried Ubuntu and used it a bit, but from what I understand this is like sudo. It lets every normal operation on the machine run in protected mode, meaning the programs can’t make major changes to the system, but it allows for easy administrative access with a password.

The Simple Trick

Make an administrator account on your Vista machine. Make it one that will not be frequently used. The actual Administrator account works great for this. Then, make your primary user account, the one that you use most often, a “Standard” user account. That way, you can use it like you normally do, but whenever you do something that requires administrative access, i.e., something that the UAC would prompt you about, you will not only have to click a button, but you will also have to enter the administrator account’s password.

This is really useful if you use both Windows and Linux, especially if you use them both on the same computer, like with a dual-boot setup. The tool is called Ext2 IFS Installable File System For Windows, it’s by Stephan Schreiber. It’s a kernel level driver (Ext2fs.sys) that allows Windows, including Windows Vista, to access drives formatted for Linux as if they were native to Windows. This means that you can use Linux-formatted drives just as you would use an NTFS or FAT-32 drive on a Windows computer. You can browse it with Explorer, save files to it, open files in it, and copy files from it.

Here is a picture of a Windows dialog box showing an Ext2 formatted drive dialog box:

As you may or may not know, I lost my iPod Touch a few weeks ago. Though I thought it was gone for good, it turns out that it was on my driveway, and when the snow melted a little bit there it was. Unfortunately, it was broken.

Still, I was glad to find my missing iPod. I looked around online for sites that would be able to fix it, but everything that I found for fixing it was priced at over $200. So then I decided that I would try and sell the Touch on eBay or somewhere else because maybe someone would want it for the parts. After a little bit of research, I found BuymyTRONICS.com, and so I sent my broken iPod to them a few days ago and today I got a payment for it.

I am very satisfied with the experience I had of selling my iPod to BuymyTRONICS.com - they truly will pay you for your broken iPod as long as there are some salvageable parts in it. I shipped my iPod in its original box to the company, which is based in Denver, CO, and I received a PayPal payment almost immediately after it was received.