power utility
Last edited: August 8, 2025power utility, or isoelastic utility, is a financial econometric is a utility that results absolute, constant relative risk aversion. i.e.: you tell me how risk averse you are exogenously, I tell you how much utility some consumption is.
constituents
- some relative risk coefficient \(\gamma \in (0,1)\), higher more risk averse
- consumption of some asset \(C\)
requirements
Utility \(U( C)\) is defined by:
\begin{equation} U( C) = \frac{c^{1-\gamma}-1}{1-\gamma} \end{equation}
additional information
As you can see, the higher \(\gamma\), the lower utility some consumption brings.
predicates, properties, and relations
Last edited: August 8, 2025a predicate or a property is a function whose range is true/false.
a relation is a property whose domain is a set of \(k\) tuples, which we call a $k$-ary relation.
preemption
Last edited: August 8, 2025We use interrupts to implement preemption, “preempting” threads in order to swap on another thread to CPU. This enables scheduling to happen.
preempting into a brand new thread
IMPORTANT: because interrupts are disabled at the beginning of the interrupt handler, and re-enabled by the end, new threads (which starts not at the interrupt handle) will not re-enable interrupts.
void interrupt_handler() {
/* disables interupts, automatically by timer handler */
// future spawns start here
context_switch(...);
/* enables interupts, automatically by timer handler */
}
void threadfunc_wrapper() {
// manually enable interrupts before first run
intr_enable(true);
// start thread's actual business
threadfunc();
}
Preference Elicitation
Last edited: August 8, 2025For for instance, we need to figure a \(w\) such that:
\begin{equation} f = w^{\top}\mqty[f_1 \\ \dots\\f_{N}] \end{equation}
where weight \(w \in \triangle_{N}\).
To do this, we essentially infer the weighting scheme by asking “do you like system \(a\) or system \(b\)”.
- first, we collect a series of design variables \((a_1, a_2, a_3 …)\) and \((b_1, b_2, b_3…)\) and we ask “which one do you like better”
- say our user WLOG chose \(b\) over \(a\)
- so we want to design a \(w\) such that \(w^{\top} a < w^{\top} b\)
- meaning, we solve for a \(w\) such that…
\begin{align} \min_{w}&\ \sum_{i=1}^{n} (a_{i}-b_{i})w^{\top} \\ \text{such that}&\ \bold{1}^{\top} w = 1 \\ &\ w \geq 0 \end{align}
Presentations
Last edited: August 8, 2025Goal: minimize cognitive load for the audience to communicate your ideas. Running examples tend to be good helpful for people.
resist the urge to tell people too much
reasonable checklist
- time
- prior knowledge
- av constraints
notice: unrelated text could be subdued.
Mykel’s Research Tips
- don’t jump directly to an outline (open with something)
- number the slides
- try to have some humor
Some techniques
- To emphasize a single idea, put them in isolation in a single sentence
- Introduce naive solutions, then show how your solution is better
- Iteratively build up the problem while showing what’s hard