jerrytsai

Joined 13 years ago

Karma
98
Submissions
49
Member since
Mar 15
"full-stack data scientist": analytics engineering -> analytics -> statistics/machine learning

email data at my username dot com

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Recent submissions

Comment · 2 years ago
Given the well-known problems with Tesla's Autopilot and (not even close) Full Self Driving, I wonder how many Tesla accidents occurred as a result of driver inattention.

Unfortunately, the study just counted accidents and did not look into what kinds of accidents occurred. It would be fantastic to be able to conduct further research.

Comment · 3 years ago
Uniqlo HEATTECH T-shirts. I wear these as first layers. They feel good and have a touch of elasticity and never wear out.
Comment · 3 years ago
Like with anything publicly traded, the price of a share is principally derived from belief. Much of this belief comes from a person projecting where the price will be in the future. With Tesla, many people and institutions projected that that price would increase in the future. Now many of them do not.

Belief in the direction of the price can come from examining the financial fundamentals of a company and the perceived value that it may increasingly generate ("fundamental analysis'). Or it can be speculative, where people believe other people will buy (or sell) more based on observed buying/selling activity ("technical analysis").

With Tesla, many investors were using their own version of technical analysis that far surpassed the valuation that a reasonable fundamental analysis would have derived and even derive today. There was and is a mania, much like there has been and there is for many forms of cryptocurrency.

The recently declining price is likely due to a collective perception that Tesla has been overpriced and, due to recent factors, that the fundamentals that justify the pricing for a share will diverge even further from its recent pricing. From a fundamental level, Tesla was unlikely to justify its recent pricing. An irony is that the earlier mania was so intense even today, after such a pronounced plunge from the start of the year, it likely remains seriously overvalued.

Comment · 3 years ago
It's unlikely that the rate of improvement, however you estimate it, will continue at the same rate. This is a Pareto effect, with marginal gains ever more difficult to obtain.

And the edge cases FSD can handle will be impaired by the sensors they do (not) install. While they make a good point that sensor fusion can impair comprehension, the removal of radar makes it hard to avoid the edge cases most calamitous.

Comment · 4 years ago
You have several questions, and they range across more than one discipline.

I'd be happy to help you narrow down a job title / job description that would help you recruit for your role. Email in profile.

Comment · 4 years ago
Blackout curtains. I and I imagine, most people, are sensitive to light. Blackout curtains prevent light from reaching your eyes, resulting in your getting more sleep.

Eyemasks are also effective, but (1) you have to tolerate having something on your face and (2) they can get dislodged while you are sleeping, rendering them ineffective.

Comment · 5 years ago
Riffing off of BugsJustFindMe's comment, what kind of privacy/security can you offer at this time? I would love to use a tool like Mozart, but I work with data that contains protected health information (PHI). PHI requires a greater degree of privacy. People working with proprietary financial information have similar concerns.
Comment · 5 years ago
Star Wars (1977).

I suspect most people who read HN weren't around when this movie came out, but I was around then.

There was tremendous hype -- the excitement that this film generated led to lines of people waiting outside movie theaters just to get their chance to see it. People would watch it and then get back into line to watch it again. I remember hearing of people who watched it 15, 20, 25 times.

Star Wars substantially advanced special effects. If you want to get an idea of what the state of special effects were in that era, watch Star Trek (the original series).

"Star Wars" felt _real_. Lightsabers, the use of a "Force" where you could physically moves things from a distance, the glissando effect when a starship goes into hyperspace-- these were all incredibly credible and mind-blowing to people back then.

Star Wars didn't just live up to its hype-- it has exceeded it, becoming a fixture in American culture, and becoming a franchise that continues to generate interest and income today.

Comment · 6 years ago
Please spare us from reports of studies with few subjects (n < 50), based on subjective self-report, and with results reported that were unintended by the study's design.

It's just p-hacking or random chance and a news outlet's way of generating clicks for itself. These findings are made public, and then almost always quietly disappear into the churn of other scientific ideas of dubious validity.

If only the follow-up, larger (n >> 50) study that later is conducted that reports negative results was as widely reported and disseminated.

Comment · 6 years ago
Ah, the 1970s and 1980s. Imagine a world with no cell phones or Internet. How are you going to get your debugging help now? StackOverflow doesn't exist.

To add to this list:

- Manuals. Reading carefully through the documentation was necessary for mastery. Both hardware and software. These were often closely associated-- you couldn't always just concentrate on one and abstract away the other.

Comment · 6 years ago
The step counting seems to work reasonably well. At least, it's internally consistent. The same workout or same route done multiple times results in no more than 5% variation when counting steps.

But the sleep tracking has been awful. A lot of days I'll get up, sit in a chair, and will surf the web for several minutes, say 45 minutes, and the watch inevitably records this time as also sleep. It's quite ridiculous and the software doesn't allow you to edit the log with the correct time. You can only delete entries, not edit them.

Comment · 6 years ago
I've found my Samsung Galaxy Watch Active2 to be hilariously incorrect with estimating sleep tracking, and I miss my Fitbits for getting that measurement.

Example: on Sunday, I woke up, drove 20 minutes to a trailhead, proceeded to strenuously hike for an hour, drove 20 minutes back. When I checked the sleep log later that day, the watch had automatically assumed I had been sleeping through the entire hike.

I like most other things about this watch, but sleep tracking is not one of them.

Comment · 6 years ago
Help with the joke? I understood the mathematician and the physicist, but not the engineer. What stereotype is being invoked?
Comment · 7 years ago
Perhaps there is a little competition component, but the idea is to stay longer in the ketosis state. If you're doing 18/6, then your body will be in a fasting state for a longer time, and the belief is that the longer your body is in that state, the more benefit you will reap.
Comment · 7 years ago
It feels wholesome and healthy to point to WeWork as a thinly-veiled re-packaging of office space and an illustrative example of what's not a "tech" company. With the collapse of their IPO, people are piling on heaps of schadenfreude.

But I can't help but wonder: how much of this is envy? Who wouldn't want to be perceived as inspirational and forward-thinking when seeking support for a pet business endeavor?

The choice of which words to use to market your idea, the value of being able to recruit people to fulfill the idea, the ability to persuade people to fund your idea. Isn't there some value provided by inspirational leadership?

Neumann may have duped a credulous Son, but he put WeWork in the position where it received Son's consideration.

I'm not excusing the grifting and self-enriching.

At the same time, I've seen situations where the charisma and the resolute determination of a leader makes a huge difference in how the team executes. WeWork may be a glaring example of what not to do, but it's also an example of the value of politicking-- of agilely positioning your endeavor to receive investment, both monetary and emotional.

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