Computer Science | Grinnell College

CHANGES: BRING YOUR OWN LUNCH. MEET IN NOYCE-3821.

Instead of discussing deep technical topics, political issues, and the downfall of society, we’ll be reading (and discussing) comics about technical topics, political issues, and the downfall of society. There is no “assigned” reading this week, but please bring or email Prof. Curtsinger a link to a web comic. A good starting point for your comics search is XKCD (www.xkcd.com), but other comics are welcome.

Discussion starts at noon on Tuesday, December 8, 2015.

Our topic at this week's Computer Science Table will be software vulnerabilities in cars, as described in this article:

Gallagher, Sean. Highway to Hack: Why We're Just at the Beginning of the Auto-Hacking Era. Ars Technica, August 13, 2015.
http://arstechnica.com/security/2015/08/highway-to-hack-why-were-just-at-the-beginning-of-the-auto-hacking-era/

Computer Science table (CS Table) is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Tuesdays from 12:00 to 12:45 in Rosenfield 224C. Contact the CS faculty for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This week at CS Table, we will consider a recent article on the potential power of Google to swing elections:

Rogers, Adam (2015). “Google's Search Algorithm Could Steal the Presidency.” Available on line at http://www.wired.com/2015/08/googles-search-algorithm-steal-presidency.

IMAGINE AN ELECTION -- A close one. You're undecided. So you type the name of one of the candidates into your search engine of choice. (Actually, let's not be coy here. In most of the world, one search engine dominates; in Europe and North America, it's Google.) And Google coughs up, in fractions of a second, articles and facts about that candidate. Great! Now you are an informed voter, right? But a study published this week says that the order of those results, the ranking of positive or negative stories on the screen, can have an enormous influence on the way you vote. And if the election is close enough, the effect could be profound enough to change the outcome.

In other words: Google's ranking algorithm for search results could accidentally steal the presidency. “We estimate, based on win margins in national elections around the world,” says Robert Epstein, a psychologist at the American Institute for Behavioral Research and Technology and one of the study's authors, “that Google could determine the outcome of upwards of 25 percent of all national elections.”

Those of you who want to delve more deeply into the issue can read (or skim) the full journal article:

Epstein, Robert, and Robertson, Ronald E. (2015). “The Search Engine Manipulation Effect (SEME) and Its Possible Impact on the Outcomes of Elections.” Proceedings of the National Academy of Sciences, 112 (33). Available on line at http://www.pnas.org/content/112/33/E4512.abstract.

Internet search rankings have a significant impact on consumer choices, mainly because users trust and choose higher-ranked results more than lower-ranked results. Given the apparent power of search rankings, we asked whether they could be manipulated to alter the preferences of undecided voters in democratic elections. Here we report the results of five relevant double-blind, randomized controlled experiments, using a total of 4,556 undecided voters representing diverse demographic characteristics of the voting populations of the United States and India. The fifth experiment is especially notable in that it was conducted with eligible voters throughout India in the midst of India’s 2014 Lok Sabha elections just before the final votes were cast. The results of these experiments demonstrate that (i) biased search rankings can shift the voting preferences of undecided voters by 20% or more, (ii) the shift can be much higher in some demographic groups, and (iii) search ranking bias can be masked so that people show no awareness of the manipulation. We call this type of influence, which might be applicable to a variety of attitudes and beliefs, the search engine manipulation effect. Given that many elections are won by small margins, our results suggest that a search engine company has the power to influence the results of a substantial number of elections with impunity. The impact of such manipulations would be especially large in countries dominated by a single search engine company.

Computer Science Table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Tuesdays from 12:00-12:45 in JRC 224C. Contact the CS faculty for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This Friday at CS TAble, we will discuss a recent document entitled “Research Priorities for Robust and Beneficial Artificial Intelligence.” The paper was selected by Stelios Manousakis, Grinnell's Artist-in-Residence for this part of the semester. Manousakis will join us for the discussion.

In selecting the paper, Manousakis noted that the paper “caused quite a stir some weeks ago as Stephen Hawking, Bill Gates, and Elon Musk—who are among those who signed it—came out publicly warning that Artificial Intelligence is the biggest threat to humanity.”

Computer Science Table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10 to 12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky, rebelsky@grinnell.edu, for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This week in CS Table, we will consider a widely used technique for using Internet services anonymously: onion routing. The leading free implementation of onion routing is Tor. The Tor Project provides a variety of software packages incorporating or building on this technique, of which the best known is the Tor browser, a Firefox derivative that uses onion routing for interactions with Web servers.

The readings are:

• Tor Project. 2015. Tor: overview. https://www.torproject.org/about/overview.html.en
• Reed, M. G., and Syverson, P. F. 1999. Onion routing [abstract only]. Prepared for the 1999 Symposium on Advanced Information Processing and Analysis. http://www.onion-router.net/Publications/AIPA-1999.pdf
• Dingledine, R., Mathewson, N., and Syverson, P. 2004. Tor: the second-generation onion router. Proceedings of the 13th USENIX Security Symposium. http://www.onion-router.net/Publications/tor-design.pdf

Packets containing copies of these readings are available on the bench near Noyce 3821.

There is also one optional reading (on-line only):

• Anderson, M. 2014. 81% of Tor users can be de-anonymized by analyzing router information, research indicates. http://thestack.com/chakravarty-tor-traffic-analysis-141114

Computer Science Table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10 to 12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky, rebelsky@grinnell.edu, for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This week in CS table, we will read the first major paper on RAID (not the bug spray, but the disk technology - Redundant Arrays of Inexpensive Disks). This classic paper not only led computer scientists to think differently about storage, but also saw wide adoption in the real world. Copies are available outside Professor Rebelsky's office.

Patterson, D. A., Gibson, G., and Katz, R. H. 1988. A case for redundant arrays of inexpensive disks (RAID). In Proceedings of the 1988 ACM SIGMOD international Conference on Management of Data (Chicago, Illinois, United States, June 01 - 03, 1988). H. Boral and P. Larson, Eds. SIGMOD '88. ACM, New York, NY, 109-116. DOI=https://dl.acm.org/citation.cfm?doid=50202.50214.

Increasing performance of CPUs and memories will be squandered if not matched by a similar performance increase in I/O. While the capacity of Single Large Expensive Disks (SLED) has grown rapidly, the performance improvement of SLED has been modest. Redundant Arrays of Inexpensive Disks (RAID), based on the magnetic disk technology developed for personal computers, offers an attractive alternative to SLED, promising improvements of an order of magnitude in performance, reliability, power consumption, and scalability. This paper introduces five levels of RAIDs, giving their relative cost/performance, and compares RAID to an IBM 3380 and a Fujitsu Super Eagle.

Computer science table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10-12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky, rebelsky@grinnell.edu, for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This week in Computer Science Table, we're exploring a different side of things. In particular, we are considering some under the hood issues in common programming areas, such as strings, memory allocation, and databases. Our reading is

Spolsky, Joel (2001, December 11). Back to Basics. Joel on Software. Web page at http://www.joelonsoftware.com/articles/fog0000000319.html.

Some questions to think about for this meeting: How are strings represented internally in your favorite programming languages? If you had a choice of how to represent strings internally, what would you do? Are all versions of malloc created equal? What flaws do you see in Spolsky's comments?

Computer science table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10-12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky rebelsky@grinnell.edu> for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Visitors to the College and students not on meal plans can charge their meals to the department.

This Friday at CS Table, we discuss a recent security failure in Unix, GNU/Linux, and Mac OS X operating systems: the Shellshock bug. Our reading is:

• Wheeler, David A. “Shellshock.” October 20, 2014. http://www.dwheeler.com/essays/shellshock.html

Computer Science Table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. We meet on Fridays from 12:10 to 12:50 in Rosenfield 224A (the Day PDR). Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Students not on meal plans can charge their meals to the department.

Contact John Stone for a copy of this week's reading.

This Friday at CS Table, we will debrief on the 2014 Grace Hopper Celebration of Women in Computing. We will be joined by alumna guest Donna House Lohmeier '96, Senior Project Manager at Qualcomm Life.

You may have seen media coverage of Satya Nadella's advice that women not ask for raises, which he quickly retracted. This brief NYT opinion piece explains why he was wrong: http://www.nytimes.com/2014/10/11/upshot/why-microsofts-nadella-is-wrong-about-women-and-raises.html

At the conference, there was far more discussion of the Male Allies panel. Here's a first-person report, which is admittedly biased: http://readwrite.com/2014/10/09/technology-sexism-male-allies-grace-hopper-celebration

And the aftermath: https://storify.com/catehstn/ghcmanwatch-mark-2

Please join us on Friday to discuss these events and our experiences at the conference.

All students are welcome to attend the discussion; you need not have attended GHC and you need not self-identify as a woman in computing.

Computer science table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10-12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Students not on meal plans can charge their meals to the department.

This Friday at CS Table, we will consider some basic issues in Evolutionary Art, art which is generated by genetic-like processes. Our reading this week is

Lewis, Matthew (2008). Evolutionary Visual Art and Design. In Romero and Machado (eds.) The Art of Artificial Evolution: A Handbook of Evolutionary Art and Music. Read the first few sections.

This chapter presents an introduction to the different artistic design domains that make use of interactive evolutionary design approaches, the techniques they use, and many of the challenges arising. After a brief introduction to concepts and terminology common to most artificial genetic design, there is a survey of artistic evolutionary systems and related research for evolving images and forms.

If you've not previously encountered evolutionary art before, you might want to look at http://electricsheep.org/, one of the more popular evolutionary art projects.

Computer science table is a weekly meeting of Grinnell College community members (students, faculty, staff, etc.) interested in discussing topics related to computing and computer science. CS Table meets Fridays from 12:10-12:50 in the Day PDR (JRC 224A). Contact Sam Rebelsky for the weekly reading. Students on meal plans, faculty, and staff are expected to cover the cost of their meals. Students not on meal plans can charge their meals to the department.