ycui1986

14 ms·

31.
by ycui1986 10mo ago
no mentioning of storage overhead? how much energy being wasted for each charging and discharging cycle?
32.
by ycui1986 10mo ago
cheap microcontrollers use RC oscillators. If they only drift a few seconds a day, that would be an achievement by itself. RC oscillator is poor enough that early days USB communication would fail if running on RC clock.
33.
by ycui1986 10mo ago
atomic clock is not expensive. they have different grades. module level atomic clock cost only $3500. the NIST hydrogen clock is very expensive and sophisticated.
34.
by ycui1986 10mo ago
Plug-in Hybrid with a small engine for charging purposes probably makes the most sense at the moment, although full electric is sexy, the range anxiety is real.
35.
by ycui1986 10mo ago
at theoretical perspective, if the X-Y plane can be addressed with 16-bit DAC by controlling laser deflection. then to seek any data with in a 4GB address space will have typical latency of 300us with the latest laser scanning technology. I
36.
by ycui1986 10mo ago
they claim to increase the speed to 500Mbps in 3-5 years. but femtosecond laser is not semiconductor. there is no exponential scaling law. femtosecond laser has been running at 80MHz for decades, they cannot just talk to the laser manufactu
37.
by ycui1986 11mo ago
So now we can have a few more failure modes. Dry rot, black mold, short caused by moisture, maybe even termite in electronics.
38.
by ycui1986 11mo ago
If anything, the most complicated problem in lithography is not EUV at all. The hardest problem is the overlay mismatch. ASML had spent decades minimizing overlay mismatch. A new player in semiconductor may claim to master EUV, or X-Ray or
39.
by ycui1986 11mo ago
with modern Chinese manufacturing, you get 2-layer PCB with via and soldermask gorgeously made for $4 in 24 hours (actually samples can even be free in China). why bother make PCB at home with all the nasty chemicals or CNC ?
40.
by ycui1986 1y ago
The Windows built-in WebDAV in explorer embarrassingly slow. Pretty much unusable for anything serious.
41.
by ycui1986 1y ago
why can’t apple just assign one engineer to get this done. it is much less effort if apple does it than the community to reverse engineer it.
42.
by ycui1986 1y ago
$3 ADCs are not cheap ADCs. Cheap ADCs are the one embedded inside cheap MCU. These days, TI sell cheap ADC/DAC that is artificially limited to 10/12-bit, but with linearity at more than 16-bit. The cost of producing bad ones vers
43.
by ycui1986 1y ago
The opamp back in the days were pretty terrible. NE5532 was the king of audio opamp for decades until the early 2000s. Modern Class D are built on advanced semiconductor processes (they are considered legacy node in the eye of Hacker News&#
44.
by ycui1986 1y ago
problem with Lumafield is their pricing. Last time I checked with them. They don't sell the CT machine. It was a lease/subscription at yearly cost of $75,000. It was not justified for what we are doing.
45.
by ycui1986 1y ago
Good for young kids to learn computer, programming, etc. It comes with free Mathematica. There are also limited game option, which is good from parent's perspective.
46.
by ycui1986 1y ago
The apple’s calculator is so bad, I cannot believe it that tech website used praise this. If you type too quick, it misses numbers. If you type too many times “+” it add too many times If you try to use it as old standalone calculator, thin
47.
by ycui1986 1y ago
the US assembler cost would be $4000 minimum.
48.
by ycui1986 1y ago
tube’s failure is such that if they survive the infant fatality, they will be more robust and reliable than transistor. The transmitters on Voyager probes have been going for 47 years. Those tube were pre-screened ones that survived from in
49.
by ycui1986 1y ago
With Rubin Observatory coming online recently, we should be able to find many more of this type of event. So, it would make sense to have a more generic probe ready in standby and wait for the next interstellar object discovery. Then, send
50.
by ycui1986 1y ago
There are also alternative proposals to use Earth's atmosphere refraction for focusing, in a geometrically similar fashion as gravitational lens. It seems more feasible than using Sun's gravitational lensing. https://en
51.
by ycui1986 1y ago
i don't think modern semiconductor device will last more than 100 years, even without all the radiation. making something last more than a few decades is very hard.
52.
by ycui1986 1y ago
does this mean we stop paying tariff tomorrow ?
53.
by ycui1986 1y ago
it is because we are not at the top of this bull market. When crypto hits Hacker News front page every other day, then you it is the peak of the bull cycle. Happened every time in all past cycles.
54.
by ycui1986 1y ago
one of the most interesting of antimatter experiments is that if they somehow showed antimatter only experience 60% gravity, that will be huge. (earlier result of measuring antimatter’s gravity showed they don’t posses antigravity, but they
55.
by ycui1986 1y ago
They should work, because they are at infinity in your eyes' perspective.
56.
by ycui1986 1y ago
Virtue One's prescription insert is $100.
57.
by ycui1986 1y ago
a few AR glasses come with adjustable knobs for nearsighted people. So, not all of them are fixed distance.
58.
by ycui1986 1y ago
some AR glasses come with built in correction up to -5.00. Beyond that, they recommend correction lens insert, so it can work for more. The built-in correction does not do astigmatism, that will require prescription insert too.
59.
by ycui1986 1y ago
one of the problem that I have using AR glasses for work is that I have to refocus my eyes every time I try to type anything, which is an annoyance. The eyes focus to the infinity on the AR glasses, but near sight when typing. This is on to
60.
by ycui1986 1y ago
ALL social media are harming children at industrial scale.

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