Taking Care of your Laptop (NYT)

 Good advice for taking care of your laptop: Make Sure the Problem is not in the Chair.

Browser "Cache" Memory

Read how browser's cache pages at the CIS 110 blog.

Browswer Cache Memory

The Browser Cache:

For efficiency reasons, browsers will sometimes cache pages/images.

I.e., , to avoid redundant downloads, the browser will store a copy of a page/image on the hard drive (along with a time stamp).

The next time the page/image is requested, it will first check the cache.

If a copy is found, it sends a conditional request to the server.
     ==>  "send this page/image only if it has been changed since the timestamp"

If the server copy has not changed, the server sends back a brief message and the browser simply uses the cached copy.

This does not always work, however.

Force Reload (in general):

But, by holding the Shift key down when you reload/refresh a page, you can force the browser to reload the page from the server, not the cache.

'Open this page outside of the Blackboard frameset & hit shift-Reload/Refresh to see the latest version'

Force Reload (in Blackboard):

In Blackboard, the shift-reload command will simply reload the Blackboard frameset rather than the page that is displayed inside the frame.

To force a reload of the web page itself you must first open that page outside of the Blackboard frame: Right-click the web page and choose This Frame > Show Only This Frame. Then use the shift-reload to see the non-cached version of the page.

How do I get into the 110 lab I want if it is full?

Image by wsh1266 via Flickr If you are unable to enroll in the course or any lab because the course is full, your only option is to Use the Wait List.

However, if you are already enrolled in the course and a lab but would like to switch to a lab that is full, here's what to do:

Go to the lab you want and ask the GTF if there's room for you. If your GTF says Yes, make sure that s/he has your name removed from your original lab and added to the new one. If the GTF says No, you will have to attend a different lab.

For labs that are full, two names may be added beyond the max on the condition that the added students bring a notebook computer or watch over someone's shoulder on days when the lab is full.

Students actually registered for the lab are guaranteed a workstation if they need one.

UOwireless Network: How To Bypass Login

Image via Wikipedia Q: I have to log in every time I use uowireless. How do I set it up so I don't have to log in every time?

A: Go to wireless.uoregon.edu and run the setup process to enable UO Secure. Using the UO Secure wireless network remembers your password and encrypts information sent between your device and our network.
From https://it.uoregon.edu/

Moonshadow Mobile: Big-Data Web Apps in Eugene

Image by Maqroll via FlickrFrom the Eugene Register Guard 9/4/11:

Eugene technology company Moonshadow Mobile is struggling to find employees to meet customer demand for its Internet-based technology programs.

Its first offerings — geared for political and government customers — quickly assemble large amounts of information gathered from U.S. Census and voter registration reports and display them on Google or Bing maps.

Using voter registration information, mapping technology, satellite imagery and data from the U.S. Census, the firm has developed a political redistricting program called Borderline, which allows users to instantly change the boundaries of political districts on maps and get population and other data on the new districts.

1-Armed Bandits && Demorgan's Law

When simulating the spin of a three-wheel slot machine, how do we detect three of a kind?





The following condition recognizes three of a kind:

var s1 = 'lemon', s2 = 'lemon', s3 = 'lemon';
alert((s1 == s2) && (s1 == s3) && (s2 == s3));

We can modify it to control a loop that spins the wheels:

       s1 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);
       s2 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);
       s3 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);

       while(!((s1 == s2) && (s1 == s3) && (s2 == s3))){
           //spin again...
       }

Applying Demorgan's Law we get:

       while(!(s1 == s2) || !(s1 == s3) || !(s2 == s3)){
           //spin again...
       }

Equivalently:

       while((s1 != s2) || (s1 != s3) || (s2 != s3)){
           //spin again...
       }

To hit the jackpot, we must spin the wheels at least once. This leads to a final, simpler version using a do-while:

do{
       s1 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);
       s2 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);
       s3 = RandomOneOf(['lemon', 'cherry', 'bar', 'donut']);
}while ((s1 != s2) || (s1 != s3) || (s2 != s3));

The do...while loop will always be executed at least once, even if the condition is false, because the statements are executed before the condition is tested.

It is a post-test loop; the while loop and the for loop are pre-test loops.

Use the do-while when you know you will repeat an action at least once.

Web Apps w/o Programming: If this, then that (IFTTT)

IFTTT. Put the internet to work for you by creating tasks that fit this simple structure:if this then that.