Shippensburg University uses ID cards to provide a number of different services on campus. This podcast talks about those services and the systems that make them work.

In order to be able to draw the red squiggles that mark spelling errors as you type, Word has to be able to determine whether a word is valid very quickly. In this episode, we explore a technique called Spelling Tries that can make the retrieval of a word from a dictionary very fast.

There are lots of interesting ways that programs can manipulate images. Some are for fun and some help the computer process the image.

Thanks to American Micro, Inc. for their support of this episode. Look at our Friends page for more information!

This episode is a Dragnet parody showing how the PA Emergency Management Agency (PEMA) uses technology during an emergency. PEMA is responsible for coordinating the responses from a wide variety of government and non-profit agencies. This requires not only technology for communcation, but also technology for analyzing the current situation

Homeland Security is a good example of a situation where the data being gathered is vast and spread across a variety of independently developed databases. Getting those databases to talk to each other is no small feat! Here are some interesting related sites:

• PA Office of Homeland Security
• Some PDF files showing how GATIR works
• Homeland Security GIS projects being developed by GeoDecisions in Mechanicsburg
• Congressional Report on Datamining and Homeland Security

There are many pieces of software that help air traffic controllers keep our planes safe. In this episode, we talk about a number of the issues that software helps address. Here are some interesting related websites:

• A video showing the air traffic in a normal day,
• Air Traffic Control by the numbers gives some interesting air traffic statistics,
• Information about Air Traffic Controllers.
• Worldwide plane traffic.
• Example ACARS messages
• ACARS in a cockpit - can you find it?
• Frequency counts of common ACARS messages.

Trilateration is a technique for pinpointing your location using the distances from you to several known locations.

Check out these sites for more trilateration examples:

• 2-d trilateration
• 3-d trilateration
• some math behind trilateration

Other places where trilateration is used:

• Air Traffic Control
• Navigation in Planes and Ships

Some computer science problems do not lend themselves to straightforward solutions. In fact, for some problems, computing the "correct" solution would take more time than we have. For these types of problems, we design solutions that will find a "good enough" solution is the amount of time we have.

One strategy for how to deal with these types of problems is genetic search. This strategy is based on the theory of evolution in biology. This podcast details that strategy with a couple of examples.

For more information, here are some interesting web links:

• an overview of genetic algorithms
• interesting animations of genetic algorithms
• a introduction to genetic algorithms in "plain English"
• the theory behind why genetic algorithms work
• a thorough description of genetic algorithms

Ever notice the bar codes that show up on your envelopes after they've been mailed? In this episode, we describe how computer scientists designed those bar codes. They are an inventive combination of fitting in a limited space while providing high reliability. For more information about these and similar encodings, check out these websites:

• POSTNET in wikipedia
• PLANET in wikipedia
• See how zip codes are layed out across the country
• Other types of bar codes

Also, check out Geek Acres!

There are many dark and evil kinds of software. In this episode, we talk about viruses, worms, trojan horses, spyware, spoofing and phishing.