Sunday, October 28, 2007

Warning: Shore break

You know there's something wrong with the sea waves when you feel the unexpectedly high force of sea waves pushing you very strong... strong enough to make you turn upside down, losing control of your body's position, and losing track of direction (can't tell up from down). This is what happened to me yesterday as i swam on Coogee Beach.

It was a bit scary at the beginning. Sometimes, the waves looked calm, but oftenly they arrive in curly waves, huge ones, with a strong push. The back current was so strong too. I had to put enough effort to hold on still.

Thinking that swimming deeper offshore would be calmer with less waves, i waited till the sea calms itself, then make the swim of it up to the point where the waves haven't break. So i did it, swam there, and had some pleasant swim on the calm sea... maybe for 5 minutes. Getting a bit tired, i decided to get back up to the beach. As i tried, i realised that i was stuck! It turned out that i was not strong enough to swim back, since there's some sort of current pulling me away from the beach. So, i swam as hard as i could whenever there's a wave, and then rest & take enough breaths when there's back current. I couldn't feel the sand bed underneath me, probably the sea was more than 2 metres deep? Anyway, the idea of shouting for help did come across my mind, luckily i didn't have too. I felt the sand on my feet, so i stood up and walked to the beach with the water level approximately as high as my neck... until,

until all of the sudden,

a massively strong wave struck me, and pushed me hard, sinking me quickly, turning me upside down, making me face upwards (or was it downwards? sorry i couldn't tell) on the sand. As i rose up and went out of the water, a lifeguard came to me and asked whether i'm alright, whether my neck's okay or not. She told me she've already warned me, but i really didn't hear her.

Just few moments later, a sign saying "Warning: Shore break" was put on the beach, with a picture of a tumbling person and a wave.

"Oh, so that's what a shore break feels like...", i talked to mysef. Among the many occasions that i swam at sea, this never happened to me before...

Friday, October 19, 2007

What i want (in particular)

Today's Friday prayers speech was very ... uhm... good. This is what the khatib told us. If you ask someone poor, what do they want? They would most likely answer they want to be rich. If you ask somebody sick, what would they want to have? A normal one would say, "i want to be healthy." If you ask a rich man, what does he or she wishes? They may answer, "I want to get richer." But suppose now, if you can ask someone who is already dead what they want, then would do you think that those dead people would answer?

Curious? Let me answer it after i tell you what I want, particularly those earthly-materialistic-oriented stuff. Here's the list:
1. Car: a Holden Commodore or a Toyota Corolla would be enough.
2. Mobile phone: a Sony Ericsson one, especially ones that are drop-resistant (is there?) and has FM radio on it. And of course, a decent camera would be just perfect.
3. Laptop: Lenovo Thinkpads. Preferably 12 inches ones, with an LPT port if possible.
4. House: a brick house with a lawn and a garage and a backyard on it so i can plant tomatoes, and can have a BBQ with friends at my very own house. Preferably in Randwick, NSW, with coastal views.
5. Motorbike: i'm not sure. Haven't followed the latest models for the past 2 years...
6. MP3 player: not really necessary. Should be included in my PDA. Oh yes! PDA...
7. PDA: a Windows-mobile based one, large RAM and a Wifi is a must. No specific brand. PDA-phone is okay too. If possible, should be easy to type in words on it.
8. Camera: DSLRs, preferably Canon EOSes.

Okay, that's more than too much to ask for. Anyway, back to the dead man's wish thing. The khotib says, one of their wishes, according to Quran, is that they want to live again just to stand up and pray a short two rakaat (unit) prayers to Allah. Simple. Yet so valuable, as what they dead people believes in. Which is also true for all of us still alive.

Another wish from a dead man is that he wants to live again and give money to charity. Because when you're dead, you bring no money with you.

I hope i can keep remembering the wisdom from the dead. I don't want to be too late to do something that i might regret later on.

Thursday, October 18, 2007

Why I didn't work on new circuit ideas

My thesis is about low swing interconnects. At the beginning, there was no clear idea on what method we should go through, or on what to do and how to do it. All that was given were circuits from other people. Then, my supervisor wants me to come up with new circuit ideas. That's fine, i thought. I straightly pursued this goal... which apparently proved fruitless due to my lack of understanding of even the basic circuits. So, my co-supervisor and I, even though a bit too late, decided that I should forget thinking about new and novel designs, but instead focus on FAIR COMPARISON. Fair comparison of different circuits appeals to me because, honestly, I don't quite believe the claims that's been made in papers proposing new 'novel' circuits. Look, there are many papers out there, claiming "...our new method shows up to 90% delay improvements and 50% power reduction than the circuit proposed in [1]..." Really? Is that true? Are you sure?? How did they compare it?

No, i wasn't sure. Then, early 2007 (can you see how late it is?) i attended an IEEE-sponsored guest lecture, by Prof. Oklobdzija, about energy-delay optimization methods. Wow, it gave me a huge insight on how to actually answer my questions. He suggested that comparing energy-delay tradeoff curve would be the best way to compare different circuit techniques.

Hence, this leads me to another problem: optimization. Well, actually in my early stages of work, i did do some limited form of optimization, which is fully trial-and-error-based. Apparently, that's not good enough, at least for me. So, my focus now is to find a formal method to design and optimize basic interconnect structures, so that i can then compare the energy-delay tradeoff between them, fair and square.

Sounds simple, but it's not. Prior to optimization, one needs to model the circuit accurately. Not just that, it should be accurate AND simple. Engineers hate complex formulas, and loves approximations. But that's sometimes impossible. No simple formulas can model short channel CMOS devices accurately these days. For instance, i had to discard all those simple basic CMOS drain current formulas from textbooks and use formulas from BSIM3V3 Spice manual instead. Many secondary effects that was neglected in the past can no longer be neglected in the 90nm technology node i am studying now. Not only does this different approach on short channel devices affect the way we estimate drain current, but also heaps of other things, most importantly for me: equivalent resistance, delay, power, and optimization methodology.

I think i'm more interested in modeling and optimization now than to actually come up with a new design. Just wish me luck so that i can submit my thesis on time. ( which is due december 2007)

Wednesday, October 10, 2007

How to know wednesdays from tuesdays

If it happens to you that you forget what day it is: a tuesday or a wednesday, all you need to do is look at the petrol price at your closest petrol station. If it's ridicolously 20 cents more expensive than yesterday, than be assured that you are indeed on a wednesday.

Thursday, October 04, 2007


Transistors are remarkable stuff. So tiny. Simple principle of operation. Yet so useful. In analog designs, they're basically amplifiers and filters. In digital world, they're simply switches. But how come i still don't understand some (maybe most) of their behaviour?? Is it because people are now making them smaller and smaller? (the newest intel processor uses the 65nm wide transistor i think) Or perhaps we now use smaller voltages? Dude, let me tell you one thing. There are so many interesting (or rather, strange and unusual) facts about these transistors that you can find out simply by running simulations on a computer, but not covered in enough details in any textbooks. Simple stuff like, in a normal inverter, why does a pull-up pmos get slower in charging a load when the source supply voltage is lowered? For extremely tiny transistors, there's also another interesting fact that lacks exposure in textbooks. In texbooks, very narrow transistors will get saturated faster with increasing Vds due to velocity saturation effect. What they do not emphazise, however, is apart from velocity saturation effect that's a function of the applied electric field across drain-source, there's another important factor that can affect drain calculation significantly. It's mobility degradation. It changes the mobility 'constant' which is actually a function of Vgs. Okay, please do get confused :-(

Wednesday, October 03, 2007

Hospital wards

The Australian public was shocked last week after a woman miscarriaged in a hospital toilet without any medical assistance for more than two hours. An inquest into this matter revealed that the Royal North Shore hospital where this incident happened did indeed suffer from some sort of mismanagement. Budgets were cut just to give a false impression of a performance boost. This makes me think, public hospitals here in NSW are just as standard as in Indonesia. A couple of days ago i went to visit a friend who needed to stay at Prince of Wales hospital Randwick, because her trombosit level went dangerously low. The ward that she was staying in was no different than the wards in Sardjito hospital back in Yogyakarta. All are standard, clean, tidy, but not too fancy. I even think that in some parts of the hospital, Sardjito is a bit more sophisticated, like the secured doors in one of its new building. And one more thing. They all smell alike. A mixture of pine o'clean and medicines, kinda hard to explain. ;-)