I would think that, by default, noise would not have a bias? Adding noise doesn't change the mean, it just increases the variance, right?
It pushes confidence bounds closer to the null hypothesis.
Readit Newsnamibj commented on Omega-3 is inversely related to risk of early-onset dementia pubmed.ncbi.nlm.nih.gov/4... · Posted by u/brandonb
namibj commented on Postgres Postmaster does not scale recall.ai/blog/postgres-p... · Posted by u/davidgu
It is bad application architecture. Database work should be concentrated in minimal transactional units and connection should be released between these units. All data should be prepared before unit start and additional processing should take place after transaction ended. Using long transactions will cause locks, even deadlocks and generally should be avoided. That's my experience at least. Sometimes business transaction should be split into several database transaction.
Your database usage should not involve application-focused locks, MVCC will restart your transaction if needed to resolve concurrency.
namibj commented on Bridging the Gap Between PLECS and SPICE erickschulz.dev/posts/ple... · Posted by u/eschu
I am not sure that I know what harmonics-based SPICE is. Is it about AC analysis?
A related mode is "11.3.12 .PSS: Periodic Steady State Analysis" in [1], though that's arguably "light mode"; the heavy mode is "HB (Harmonic Balance Analysis)
Calculates steady states of nonlinear circuits in the frequency domain.
General Form .HB <fundamental frequencies>" as implemented in Xyce[0]:
Harmonic balance (HB) is a technique that solves for the steady state solution of nonlinear circuits in the frequency domain. In harmonic balance simulation, voltages and currents in a nonlinear circuit are represented by truncated Fourier series. HB directly computes the frequency spectrum of voltages and currents at the steady state solution. This can be more efficient than transient analysis in applications where a transient analysis may take a long time to reach the steady state solution. In particular, HB is well suited for simulating analog RF and microwave circuits.
HB supports an unlimited number of independent input tones for driven circuits in both serial and parallel builds of Xyce. The output of HB analysis is the real and imaginary components of voltages and currents in the frequency domain. Xyce also provides time domain responses of a circuit. By default, the numbers of samples in both time and frequency domain outputs are the same. However, the number of time domain samples can be much larger than the number of frequency domain samples by setting numtpts in .options hbint. This enables the users to use a small number of harmonics for each tone and produce well-resolved results in time domain.
[0]: https://xyce.sandia.gov/documentation-tutorials/ [1]: https://ngspice.sourceforge.io/docs/ngspice-html-manual/manu...
namibj commented on Teaching my neighbor to keep the volume down idiallo.com/blog/teaching... · Posted by u/firefoxd
What do you mean? A fireplace can last far far longer than that timespan and it's efficiency is not tied to it's age.
If you don't want to replace it after 15 years, buy one that will pass emissions for the next 30 years.
namibj commented on Postgres Postmaster does not scale recall.ai/blog/postgres-p... · Posted by u/davidgu
That many long-running transactions seem like a pretty unusual workload to me and potentially running into isolation issues. I can see running a few of these, but not a lot, especially at the same time?
A few (single digits, maybe low double digits) per database CPU core isn't necessarily too much, of course the pattern can be conflict-heavy, where it would be problematic, but this is not about absolute concurrency but about concurrency needed to saturate CPU.
namibj commented on Postgres Postmaster does not scale recall.ai/blog/postgres-p... · Posted by u/davidgu
In a properly optimized database absolute majority of queries will hit indices and most data will be in memory cache, so majority of transactions will be CPU or RAM bound. So increasing number of concurrent transactions will reduce throughput. There will be few transactions waiting for I/O, but if majority of transactions are waiting for I/O, it's either horrifically inefficient database or very non-standard usage.
If you aren't hitting IO (I don't mean HDDs) on a large fraction of queries you either skipped a cache in front of the DB or your data is very small or you spent too much on RAM and too little on your NVMe being not a bottleneck.
The thing about social security is that it was supposed to be used for a fairly narrow system, and the physical cards even have text like "not to be used as identification" on them. And then we used it for that anyway
The German equivalent to the SSN in it's ubiquity, the "federal tax id", is illegal to use for non-tax purposes.
As a German that feels about correct.
namibj commented on Postgres Postmaster does not scale recall.ai/blog/postgres-p... · Posted by u/davidgu
You can't process significantly many more queries than you've got CPU cores at the same time anyway.
Much of the time in a transaction can reasonably be non-db-cpu time, be it io wait or be it client CPU processing between queries.
Note I'm not talking about transactions that run >10 seconds, just ones with the queries themselves technically quite cheap.
At 10% db-CPU-usage, you get a 1 second transaction from just 100ms of CPU.
namibj commented on When internal hostnames are leaked to the clown rachelbythebay.com/w/2026... · Posted by u/zdw
> Admittedly, most residential ISPs block all SMTP traffic, and other email servers are likely to drop it or mark it as spam, but there's no strict requirement for auth.
Source? I've never seen that. Nobody could use their email provider of choice if that was the case.
They don't do DPI, they just look at the destination port.
And that's why there's a separate port for submission to mail agents where such auth is expected and thus only outbound mail is typically even attempted to be submitted to.
Technically local delivery mail too, e.g. where the From and the To headers are valid and have the same domain.