Mark L. Stone's Avatar

Mark L. Stone

@marklstone.bsky.social

Stochastically modeling, analyzing, and optimizing for more than 4 decades.

180 Followers  |  19 Following  |  16 Posts  |  Joined: 15.11.2024  |  1.9075

Latest posts by marklstone.bsky.social on Bluesky

For me, GenAI's like Wiki on steroids. Drill deep & broad, go w/flow (2nd order conditions for nonlinear SDP when stationary point not exact) - interactive learning w/ renaissance teacher who's not always right. Critically think about what GenAI says; call it out when wrong, which it usually admits.

13.10.2025 05:38 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

As MIT undergrad, did UROP on Dial-A-Ride in Center for Transportation Studies. Hani sat 5 feet from me. His 1st OR course used H&L. Told me was hardest book/course he ever had. That's how I first heard of OR. I skipped H&L; undergrad Math right to OR PhD courses at MIT (as undegrad), then Stanford.

13.10.2025 05:09 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

det(exp(X)) = exp(tr(X)). Remarkably, the RHS does not involve off-diagonal elements of X.

19.09.2025 00:13 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Often overlooked: the price of some paths may be highly uncertain.

09.04.2025 12:07 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Does this technique allow construction and SC proof of a barrier for Symmetrized Quantum Relative Entropy (SQRE), defined as SQRE(A,B) = QRE(A,B)+QRE(B,A) ? This would hopefully allow use of a single symmetric cone instead of 2 asymmetirc cones?

11.02.2025 12:54 β€” πŸ‘ 1    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0
Preview
CVX Forum: a community-driven support forum Software for disciplined convex programming

Very nice. It would be interesting to see how many "unsolved" (Erling's challenge) problems on ask.cvxr.com could now be conic reformulated, and to what extent computer algebra type techniques might help in finding such refomulations, along the lines of ask.cvxr.com/t/ph-d-thesi... .

07.02.2025 12:52 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

I note in passing that I read a new paper today which had 2 instances of "we remark in passing". That's a writing style I associated with decades past, such as a paper I coauthored in "Operations Research" in 1983 which I note in passing used "we note in passing" (attributable to my older coauthor)

18.01.2025 17:25 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Now fixed (at least for me).

Yes, water will freeze at 27 degrees Fahrenheit because the freezing point of water is 32 degrees Fahrenheit, so any temperature below that will cause water to freeze; 27 degrees is below 32 degrees.
Key point: Water freezes at 32 degrees Fahrenheit.

17.01.2025 18:19 β€” πŸ‘ 2    πŸ” 1    πŸ’¬ 0    πŸ“Œ 2

Can single precision cut the mustard on first order methods, such as PDHG for LP (perhaps if followed, if needed, by some type of repair step or crossover in double precision)?

19.12.2024 22:03 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

Sorry. I meant single vs. double precision.

19.12.2024 20:49 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

What precision is used on GPU?

19.12.2024 19:28 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

Corollary: If if A and B are symmetric d x d matrices and B is positive definite, then AB is diagonalizable.

17.12.2024 21:22 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0
Preview
High Crimes and Misdemeanors in the Analysis Biz, Part 1: My Funny but True Taylor Series Stories 1. Startling New Phenomenon in Cosmology May 1980: An M.

www.linkedin.com/pulse/high-c...

10.12.2024 01:54 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

How does energy (electricity) used to solve the problem compare between GPU and CPU?

22.11.2024 17:30 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 1    πŸ“Œ 0

SR1 is a fairly well-known Quasi-Newton update. Most frequently used in conjunction with Trust Regions on indefinite Lagrangians.

SR! Quasi-Newton update is same as SR1, except for holding on to the shift key too long after the R. Most frequently used by older people with declining visual acuity.

18.11.2024 18:50 β€” πŸ‘ 0    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

A crappy simulation is a crappy simulation, whether or not it's called a Digital Twin.

18.11.2024 18:47 β€” πŸ‘ 2    πŸ” 0    πŸ’¬ 0    πŸ“Œ 0

@marklstone is following 19 prominent accounts