My JLab

A hugely underestimated and rarely used feature that Johns Hopkins offers to students is My JLab. My JLab supplies a virtual desktop interface (VDI) from a third party provider to students so they can use applications and software that are either unavailable to private users, or too expensive for college students to buy. Some of these applications include MatLab, Mathematica, PyMol, SPSS, R, and various programming applications. It's easily accessed to any student connected to the Hopkins wireless network; all that is needed is your JHED and the ISIS password you use. To access this, log in at myjlab.jhu.edu.

First you will be asked to install the Citrix XenDesktop software to your laptop, tablet, or smartphone. By clicking the "agree" box and then installing it, you will be able to access the JLab software my going to the website. If you don't want to install it, the VDI won't be able to work on your computer. It will look something like this:

What the Citrix screen will look like the first time you go to the website. Install the software to use the VDI.

 After you install the software, refresh the page. You will get a log-in page that looks like this:

The login screen for the Citrix XenDesktop VDI.

After entering your JHED and password, your entire screen will change, and you should see something that says "Window 7 Lab" starting up (even if you're on a Mac!). This is because you are actually migrating to another "computer" of sorts. Remember the articles about cloud computing? The XenDesktop VDI is designed to allow a user to access a giant pool of applications located in a cloud. This cuts down on licensing fees and allows more people to use the software. It also affords each user a limited amount of space on this cloud. Because every user accesses the same cloud, the format is always in the same operating system (Windows 7), no matter what the accessing OS is.

The VDI desktop when you log in to XenDesktop.

To use a program, go to the start button and simply type in the name of the program you want to use. You may even discover new associated software for the program you're using. You can open the program and pin it to the toolbar so you don't have to look so hard next time. The VDI saves user preferences like this, but it won't save files that you put on the desktop! It only saves files within the virtual hard drive.

Because this is technically a different machine, the files you store on the VDI hard drive will not be accessible by your original desktop. You can write files to your original hard drive from the VDI, but only if you give it read/write access. Even then, there may be an issue when accessing the file on the original hard drive. In general it's easier just to save the files to an external drive (flash drives are definitely useful here!) and then move them over back from the drive to your original hard drive.

But how do you get back to the original desktop once you have the VDI desktop up? If you look up at the top of the screen, you should see a black arrow. Because it's not a projection of the VDI desktop and a part of the software running from your original desktop, it doesn't show in the above picture. Pretty cool, right? Anyway, if you click the arrow, a menu will drop down. The leftmost icon is what you want to hit if you want to go back to your original desktop. The other icons aren't used often, but disconnecting from the VDI won't log you off of the desktop. If you want to keep a program running, use the disconnect feature to close out of XenDesktop. If you are done for a while, go down to the start button and log out.

Once you get back to your original desktop, you will see this icon on the bottom of your screen:

This is the icon for the XenDesktop software, and you can click it at any time to go back to the VDI. Your browser window will be replaced with a new window, and this icon will be in the middle of it.

The icon on the browser window.

If you, for whatever reason, suddenly get disconnected from the VDI, you can click on the blue screen shown above to relaunch the XenDesktop software. When you're done for good, just close the browser window.

That's a run down of XenDesktop here at Hopkins. For more information about MyJLab, go here: http://web1.johnshopkins.edu/classrooms/kriegerlab/myjlabsoftware.html. If you experience any problems or have any additional suggestions, write them in the comments. Thanks everyone!

Hopkins does the Harlem Shake!

Hopkins has retained its title of one of the most technologically relevant schools, especially after creating their version of the dance craze called the Harlem Shake!

Here's the youtube link: https://www.youtube.com/watch?v=TikJdWYwNCQ

No kitties or people were harmed in the making of this video.

Asteroid Interaction

Welcome back to Tech Blog Tuesday at Johns Hopkins University! We're excited to be starting up the tradition again in 2013. Posts will be coming more frequently and stem from a variety of hot-button topics.

Last Friday, two very interesting events happened to the Earth and the immediate region in space surrounding it. One, the asteroid classified as 2012 DA14 passed by Earth at a distance of 17,210 km, which is closer than the moon is to the Earth. It's the first time an object of this size has been detected before it passed this close, and was discovered last year by a Spanish telescope.

NASA/JPL-Caltech/Associated Press - This image provided by NASA/JPL-Caltech shows a simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Friday, Feb. 15, 2013. The 150-foot object will pass within 17,000 miles of the Earth. NASA scientists insist there is absolutely no chance of a collision as it passes.

But it wasn't the only thing in the sky that day.

The second space-relevant thing to happen last Friday was the meteor that entered into the atmosphere over Russia, flew overhead at about 20 miles at 40,000 miles per hour, released a ton of energy, and injured about 1,200 people from its shock-wave. When you learn very few people have ever been injured by meteors, coupled with the frequency of a meteor impact of this size is once every century,you begin to realize how astronomically small the odds of this incident happening are--pun intended.

For all those who wonder if the Russian meteor was somehow related to 2012 DA14, consider the fact that the asteroids came from opposite directions. “There is no relation there,” said Paul Chodas, a scientist with NASA’s Near Earth Object Program. “It seems like we’re in a cosmic shooting gallery here. There were two very rare events happening on the same day. Pure coincidence.”

Russian witnesses describe the meteor's fall as a streak across the sky, with a smoke trail "similar to a jet's but much larger." The mach-52.5 meteor caused an immense disturbance in the air surrounding it as it plummeted, creating a huge shock wave that traveled slower than the light and roaring sound of the meteor. Many were drawn to the windows by its intense and unearthly light, but when the windows imploded from the shock wave, hundreds were showered with broken glass. It is for this reason that so many were injured, not because the meteor exploded and hit people.

A photo provided by Chelyabinsk.ru shows the meteor’s trail over Chelyabinsk on Friday. Its passage unleashed sonic booms.

The Russian science community says the meteor was about 10 feet wide and weighed about 10 tons, but American estimates based on low-frequency sensors put the meteor at a much larger size: 50 feet wide and 7,000 tons. Based on the differences in the reported values, it is possible that the density of the asteroid is unusually high, causing huge disturbances in the low-frequency sensors. More will be known once the landing place of the meteor is discovered, but considering it exploded as it passed over, that may be more difficult than it originally sounds.

Although it exploded 15-20 miles above the ground (higher than the troposphere, the part of the atmosphere that contains all weather), it still unleashed a huge amount of energy equivalent to about 300,000 tons of TNT. To put that into perspective, the Hiroshima bomb was about 15,000 tons of TNT in destructive power.

Even when you assume the Russian's small size estimate, a rock traveling at that speed and that size could cause a crater about a kilometer (.62 miles) in diameter. When geologists find it, they'll have a field day. It's a huge chance to study something new and exciting, something to always hope for!