An Algorithmic and Social Introduction to Computer Science (CSC-105 2000S)

Class 41: Models of Computation

Back to Evaluating AI. On to Costs of Computing.

Held Monday, April 17, 2000


Today, we begin to consider a variety of models of computation, including finite automata and turing machines.

Question 41 for discussion today: Summarize the most important thing you've learned from the reading.

Question 42 for discussion tomorrow: What implications do you see in the existence of NP-complete problems?




Short News Blurbs

Some short notes you might like (taken from ACM news)

Microsoft's Security Flaw

"Microsoft Acknowledges Its Engineers Placed Security Flaw in Some Software"

Wall Street Journal (04/14/00) P. A3; Bridis, Ted

Microsoft engineers deliberately placed a file in some of the company's Internet-server software that could allow hackers to obtain Web site management files from thousands of sites, the software giant admitted yesterday after two security experts reported the flaw. The secret password violates Microsoft's policy and is a firing offense for the still unidentified programmers who wrote the code, said Microsoft security response center manager Steve Lipner. Microsoft will warn users through email and on its Web site to delete the file named "dvwssr.dll" that is installed on the company's Internet server software with Frontpage 98 extensions. Many Web sites use the software, and hackers could use the password to access site management files, which could lead to the discovery of information such as credit card numbers. The three-year-old software was written at the height of the browser wars between Microsoft and Netscape, and the illicit code includes a slur referring to Netscape engineers as "weenies." Security experts say the file is a major security threat, especially to commercial Internet-hosting providers.

The URL I received for this article was for an MSNBC site. Perhaps not so surprisingly, the article was gone when I went to look for it.

Privacy in the Workplace

"Your Boss May Be Watching"

Medill News Service (04/12/00); Maestri, Nicole

Almost three-fourths of large companies in the U.S. monitor their workers' use of communications technology, including Internet surfing, PC use, email, and phone calls, according to a survey released by the American Management Association on Wednesday. Workplace surveillance has drastically increased since 1999, when 45.1 percent of companies monitored their employees, the survey says. The number of companies that review employee email has tripled to 38 percent since 1997. In addition, 54 percent of respondents say they monitor Internet connections. Doug Fowler, president of PC monitoring software firm SpectorSoft, says 54 percent sounds too high and suggests that companies might be referring to filters and other ways of blocking sites rather than actual tracking of Internet use. Employers are concerned that misuse of technology reduces productivity and poses liability threats. Almost 20 percent of the survey's respondents say they have terminated workers for abusing technology, says the association. Although many workers believe their communications are private, companies are legally able to record and review email messages, phone calls, PC use, and Web surfing that take place on corporate equipment.,1510,16252,00.html


Today, we'll try a somewhat different approach to the technical material. Instead of having me go over the material, it's up to you as a class to figure out what's going on in these chapters. We'll continue this strategy for the rest of the week.

Some basic questions to get you started:



Saturday, 22 January 2000

Monday, 17 April 2000

Back to Evaluating AI. On to Costs of Computing.

Disclaimer Often, these pages were created "on the fly" with little, if any, proofreading. Any or all of the information on the pages may be incorrect. Please contact me if you notice errors.

This page may be found at

Source text last modified Fri Apr 21 17:09:44 2000.

This page generated on Mon Apr 17 09:34:41 2000 by Siteweaver. Validate this page's HTML.

Contact our webmaster at