Ack!

Date: Friday

Apparently I'm not good at keeping track, it is now Sunday (when I'm writing this).

Today lecture is similar to the lecture we did a few weeks ago regarding how PWO, PCI and PSI relates to each other, we started first by deriving a regular expression given a DFSA, and show that how regex, NFSA, and DFSA also has very close relationships with each other.

I still have trouble grasping the purpose of epilson transitions in NFSA, is it just some kind of a placeholder?

I haven't started working on assignment 3 yet, I looked at it a long time ago, thought about it, but haven't written any conceivable proofs regarding it. It doesn't seem that hard, I just have trouble formulating the definition of the Kleene star (question 3) in the head, and how I should go about to prove it. Right now, I'll take a rest - a brain's always clearer when you're not tired.

Pointless entry

Ah, so I finally understands what NFSA is, and how it relates to DFSA in today's lecture.

The massive amounts of epsilon transitions confuses me a little, but everything makes sense with a picture of a FSM.

Still cannot grasp the ideas behind many of the regular expression symbols, but it should be cleared when I worked through problem set 6 and assignment 3.

Should start on both above-mentioned work.

A new week

Due to my poor eyesight for today, I'm unable to write everything down, so I'll recall with my memory of today's lecture.

So we started to prove that a Deterministic Finite State Automata (DFSA) is correct given what the machine supposed to do and a proper string in the alphabet. The prove itself, like the proof of correctness, is rather long but not hard.

Next, we went on to the definition of NFSA (what's the N stands for anyways?), which I (unfortunately) can't see too clearly what it is about, I assume it is quite similar to that of the DFSA.

I'll take a break today, got to rest my eyes.

second midterm....

Date: Friday

I see a pattern correlating with me and the midterm (of all kinds):
- When I'm not confident, when I feel I'll do bad on it, the mark generally are higher than what I expected.
- When I'm confident, when I feel alright about the midterm, the mark is lower than what I expected (well... not really, just lower then average... overall).

I don't get it, so maybe I'll just stay insecure about every kind of of written exam, there's much more improving I needed to do to get better on it.

Today's class is gone basically into course evaluation and handing back problem sets and midterms, since there are not much to write about on Friday, I'll finish here.

FSAs

I think I finally can grasp the usage and idea behind regular expressions now, so I think this will propel me quickly in understanding the lecture.

Today's class is rather interesting - more deterministic finite state automata, it was so interesting that I might just search for the same program that Danny used in the class today and the previous lesson before that.

But the darker side, I'm still a bit confused about the definition of language and a set of alphabets (afterward when I'm doing my problem set 5 I finally understand the difference between them), so there's hopefully no problem with this topic from now on. All I need is to spent time wisely and catch up with my work.

*Sigh*...

I've suffered a major sleep deprivation today finishing off A2 for 207, sleeping at 4 a.m. and waking up at 8 a.m., not that it's a big deal for other people (who I guess have experienced worst) who had been through this many times, but I just don't feel like myself today.

Strangely, it's the opposite that happened. Usually I'm awake mentally but tired physically, but today I felt I can stay through the lecture without completely collapsing mid-way through the lecture, yet I have trouble concentrating mentally, oh well... this happens only today I guess...

The lack of practice for today's topic (regular expression/finite state automata) certainly had me at a loss yet again, this is amplified more by the lack of sleep explained above. With enough time (I still haven't studied for the MAT 223 quiz on Thursday yet) I'll have to try harder reviewing those to get a better grasp of this and prevent me from falling seriously behind.

Then there's another problem set, oh great..., well..., at least my workload eases up a bit after this week.

Minor complaint here: It just seemed like this course, together with STA 247, has been giving us weekly work throughout the semester, it's hard as it is for me to went through this (plus other courses) without a break or a two in between, plus I'm behind in all of my courses yet again, oh time... you are certainly very elusive when I need you.

Reflections on the second midterm

Date: Friday

I still didn't do quite well, but at least I'm more confident in my proofs now having been through two months of inductive proof training. The reason why I didn't get a chance to finish writing up the midterm is because I spent way too much time on question 2 - trying to make sure all the cases work. I managed to find the loop invariant and write out the proof structure, but I handed the midterm in early because I figured there's nothing you can do in less than 1 minute. Question 1 otherwise was easy and relatively straightforward, yet I tripped myself a bit (overwhelmed?) at the beginning when I couldn't figure it out.

I just hope that I can continually to improve all the way to the exam.