multi-core CPUs

Finally, actually multitasking: starting in mid 2000s, multiple cores are finally more common. management between cores is crucial

Moors Law Break Down

• we have reached much of the limits of the speed of a single core
• instead, we have to have more cores—which requires more management to take advantage of

More kinds of Cores

• “performance” vs “efficiency” cores
• needs to schedule for different tasks: not just who on what core, but who on what TYPE of core

Other Hardware

Specialized hardware in these chips, which is required for scheduling.

Clock math.

We say that \(a\ \text{mod}\ b = r\) if \(a=bq+r\), such that \(b>0\) and \(0 \leq r <b\). More specifically, we denote:

\begin{equation} a \equiv a’\ \text{mod}\ b \end{equation}

if \(b|(a-a’)\).

additional information

basic modular arithmetic operations

\begin{align} (a+b)\ \text{mod}\ c &= ((a\ \text{mod}\ c) + (b\ \text{mod}\ c))\ \text{mod}\ c \\ (ab) \ \text{mod}\ c &= ((a\ \text{mod}\ c) (b \ \text{mod}\ c)) \ \text{mod}\ c \end{align}

examples of modular arithmetic

If \(a\ \text{mod}\ b = r\), \((-a)\ \text{mod}\ b = -r = b-r\)

goal: Drug Resistance could be more hampered by developing drugs that actually fit in the sub-strait envelope (i.e. if a virus develops a change to the drugged area, it should also stop working)

takeaway: to design inhibitors, it sticking out (“protrusion”) of the substrate envelope causes easy areas of mutation that will confer Drug Resistance, therefore, design drugs that try to stay within substrate envelope to ensure a higher degree of imperviousness to mutation (i.e. if the envelope changes well the virus is going to not do its job either)

MOMDP are POMDPs where some parts of the state are fully observable.

Motivation

scaling up POMDPs is really hard: exponential curse of dimensionality. Even discretization will cause the number of beliefs to really blow up.

Some of the state isn’t uncertain, some others are bounded uncertainty: this REDUCES scale a lot.

Solving

Solving the algorithm uses SARSOP, or any point-based system. Instead of sampling the full belief state, however, we sample from a tuple \((x, b_{y})\), whereby \(x\) is the observable part and \(b_{y}\) is the unobservable part.