Quiz eight notes
Importance of concepts from probability is rapidly increasing in CS:
Randomized algorithms (e.g. primality testing; randomized search algorithms, such as
simulated annealing, Googles PageRank, just a random walk on the web!) In
computati
Quiz nine notes
1. Introduction
Internet Exchange Points
Physical level-2 infrastructure
Allows different ISPs to exchange traffic through mutual peerings
Few staff, automated monitoring
In Europe, most IXPs form part of Euro-IX (European Internet Exchang
Quiz four notes
Evaluation of Postfix Expressions
Easy to do with a stack
given a proper postfix expression:
get the next token
if it is an operand push it onto the stack
else if it is an operator
pop the stack for the right hand operand
pop the stac
Quiz five notes
What is Computer Science?
Computer Science is the study of computers (?)
This leaves aside the theoretical work in CS, which does not make use of real computers,
but of formal models of computers
A lot of work in CS is done with pen and
Quiz One notes
Parallel Programming 1988
At the 1988 Salishan conference there was a bake-off of parallel programming
languages trying to solve five scientific problems
The Salishan Problems (ed. John Feo, published 1992) investigated four
programming la
Quiz seven notes
Encode:
C = Me (mod n)
M is the plaintext; C is ciphertext
n = pq with p and q large primes (e.g. 200 digits long!)
e is relative prime to (p-1)(q-1)
Decode:
Cd = M (mod pq)
d is inverse of e modulo (p-1)(q-1)
Graph Theory
Graphs and Ne
Quiz two notes
From the NRC Report on The Future of Supercomputing:
Platforms, software, institutions, applications, and people who solve
supercomputing applications can be thought of collectively as an ecosystem
Research investment in HPC should be inf
Quiz three notes
What we do know how to do:
Build systems with dynamic load balancing (Cilk) that do not respect locality
Build systems with rigid locality control (MPI, UPC, etc.) that run at the speed of
the slowest component
Put the programmer in co
Quiz ten notes
Energys Impact
Datacenters are growing in size
100k servers + millions of cores possible
Energy demands also growing
Cost of energy is increasing
Estimates of >30% of TCO and rising
the emissions of the airline industry
Reducing Energys Im
Quiz six notes
-8885356
How would you write an algorithm to solve this problem? Assume the basic operation is
adding one-digit numbers.
Types of Operations
Basic operations
Wet hair
Rinse
Turn on VCR
Conditional operations
If batter is too dry add
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>NoSuchKey</Code><Message>The specified key does not exist.</Message><Key>01ba5629644dcabaee0904c399633899767b99c1.txt</Key><RequestId>CA88F468421205AB</RequestId><HostId>H4N7VM49IUriTiAoUwmpk+xM2aZcFzOLj