My Rambling Thoughts

Solved Rubik's Cube at last

I finally learn how to solve a 3x3 Rubik's Cube after some 42 years. It is a minor "Achievement Unlocked" moment for me. :clap:

I first followed the instructions that came with the cube. It works, but there are too many rules to follow. (*) On YouTube, you'll find the "Beginner's Method" which has more steps but fewer rules.

(*) It uses the Beginner's Method for the first two layers and the last layer cross, then switches to some sort of OLL (Orient Last Layer) and PLL (Permutate Last Layer). It has one algo for OLL only, need to repeat the same algo several times. It has two algos for PLL, also need to repeat several times.

I had some difficulities following the first video that I picked, then I was able to follow a second video. What was funny was that when I went back to watch the first video, I found that it had the exact same steps!

People could solve the Rubik's Cube in less than a minute using the Beginner's Method. However, they are not using the "absolute" Beginner's Method. There are three ways to speed up:

  • Shortcuts
  • Finger tricks
  • Lookahead

Shortcuts are ways to solve faster if certain conditions are met. They are faster, but you have to learn more algos. And more practice to be actually faster!

Finger tricks are using optimal finger movements to move the pieces fast.

Lookahead is to be able to solve the next step or stage without pausing.

Once you master the above, you have max'ed out the Beginner's Method. Then it is time to move to advanced methods. The next step up from the Beginner's Method is F2L (First 2 Layers), where you solve the first two layers directly. This is key to getting sub-30s time.

How to bring down COE quickly

LTA brought forward the 5-year deregistration COEs in order to increase the quota today. It is a one-time fix.

My suggestions.

Commerical usage will pay 50% more. If COE is $50k, commerical cars will pay $75k.

(The Transport minister continues to deny that commerical cars contribute to high COE. In typical PAP deflection, he said they make up only 10% of the car population. What is important is their makeup in COE bidding today, which is 30% to 40%.)

New cars will be fitted with new IU that deducts double ERP and parking. Existing cars that have their COE renewed will be charged double as well. Make usage more expensive. Shift the cost from ownership to usage.

Combine cat A and B. Many people ask for more categories. Instead, we should reduce the number of categories and pool the quota together. Have a formula that penalizes "big" cars, e.g. 50% higher COE for cars with OMV over $30k, 100% higher COE for cars with OMV over $50k and so on.

Must deposit 30% of last bid price upfront (min $10k). This is less a deterent than you may expect, because people can take personal loan for it.

Pay what you bid, up to 120% of the COE price. The cutoff is no longer a line, but a band. Hopefully, this will make people think harder cos they are paying more for the same piece of paper.

Pay 25% more for 5-year COE renewal (min $10k). Make it less attractive to renew COE and hence will return to the quota.

But don't think that COE will crash. The price depends very much on what people are willing to pay.

Air-con broke down again

In the first week of April, my air-con broke down again. Everything seemed to work, but it was not blowing cold air. There were two notable points:

  • It did blow cold air at the start and every hour or so
  • The compressor was shaking quite hard and there was no wind from the fan
  • It also felt a bit warmer than usual

The air-con compressor is Daikin MA56EV16. Specs: non-inverter, 20,267 BTU/hr, cooling capacity 5.94 kW, current 7.6A, sound level 54 dB(A).

Indoor unit: Daikin FT25DVM. 9k BTU/hr. Cooling capacity 2.6 kW. Airflow 247 cfm. Sound level 36/29 db(A). Power 815W.

The compressor can only cool two rooms simultaneously. It can cool 3 rooms at 74% efficiency and 4 rooms at 56% efficiency.

Can I change the compressor to an invertor unit keeping everything else? ChatGPT says yes, but the air-con technician says no.

In the end, it turned out that the fan blade shattered into pieces. That explained the exploding sound I heard that night before — I found the air-con was not cold the next morning.

The blade costed $42 new, but there was no stock left. The technician found a 2nd one for $85. And he recommended to change the motor (also 2nd hand) as well for $225. (He insisted on it.) It was plain just changing the blade alone was not profitable for them.

(The motor was still available new for $255, but they would charge a further installation fee of $60 — I called the first air-con shop I found online. Maybe that was not a good idea.)

As they were replacing the parts, I felt that the replacement motor looked older than mine! It also made a low whining sound when in operation.

If the air-con breaks down again, and parts get harder and harder to find, I will need to replace the whole system. It will be a major pain. This air-con system is 13 years old with two breakdowns.

Minimum requirements: inverter, 36k BTU/hr.