Jim Luedtke
@optimizer.bsky.social
Professor, Stochastic and Integer Optimizer, Dad
Reposted by Jim Luedtke
our #openaccess book on "branch-and-price" is finally published; you can download it here link.springer.com/book/10.1007...
#orms @springernature.com
#orms @springernature.com
February 10, 2026 at 8:27 PM
our #openaccess book on "branch-and-price" is finally published; you can download it here link.springer.com/book/10.1007...
#orms @springernature.com
#orms @springernature.com
Reposted by Jim Luedtke
1/ ProPublica collected handwritten letters in mid-January from children held at the Dilley Immigration Processing Center, the same facility where 5-year-old Liam Conejo Ramos was taken.
Hundreds of kids are still detained.
We’ll let the children’s words speak for themselves. 🧵
Hundreds of kids are still detained.
We’ll let the children’s words speak for themselves. 🧵
February 9, 2026 at 12:25 PM
1/ ProPublica collected handwritten letters in mid-January from children held at the Dilley Immigration Processing Center, the same facility where 5-year-old Liam Conejo Ramos was taken.
Hundreds of kids are still detained.
We’ll let the children’s words speak for themselves. 🧵
Hundreds of kids are still detained.
We’ll let the children’s words speak for themselves. 🧵
Reposted by Jim Luedtke
📣 𝗣𝗼𝘀𝘁𝗱𝗼𝗰 𝗼𝗽𝗲𝗻𝗶𝗻𝗴𝘀 𝗶𝗻 𝗺𝘆 𝗴𝗿𝗼𝘂𝗽!
I’m looking to hire 𝟭–𝟮 𝗽𝗼𝘀𝘁𝗱𝗼𝗰𝘀 to work with us across the group’s research areas, including:
🤖 Deep reinforcement learning
🚦 Traffic modeling & control
🧠 Neural combinatorial optimization
I’m looking to hire 𝟭–𝟮 𝗽𝗼𝘀𝘁𝗱𝗼𝗰𝘀 to work with us across the group’s research areas, including:
🤖 Deep reinforcement learning
🚦 Traffic modeling & control
🧠 Neural combinatorial optimization
Prospective Members
Faster, evidence-based decisions for sociotechnical systems
cathywu.github.io
February 3, 2026 at 10:00 PM
📣 𝗣𝗼𝘀𝘁𝗱𝗼𝗰 𝗼𝗽𝗲𝗻𝗶𝗻𝗴𝘀 𝗶𝗻 𝗺𝘆 𝗴𝗿𝗼𝘂𝗽!
I’m looking to hire 𝟭–𝟮 𝗽𝗼𝘀𝘁𝗱𝗼𝗰𝘀 to work with us across the group’s research areas, including:
🤖 Deep reinforcement learning
🚦 Traffic modeling & control
🧠 Neural combinatorial optimization
I’m looking to hire 𝟭–𝟮 𝗽𝗼𝘀𝘁𝗱𝗼𝗰𝘀 to work with us across the group’s research areas, including:
🤖 Deep reinforcement learning
🚦 Traffic modeling & control
🧠 Neural combinatorial optimization
Reposted by Jim Luedtke
A reminder to the news media: “conflicting accounts” is what you say BEFORE the incontrovertible video evidence appears. After that, your job is to ask why one side is lying, not to repeat the lie and pretend no one knows the truth.
January 25, 2026 at 12:28 PM
A reminder to the news media: “conflicting accounts” is what you say BEFORE the incontrovertible video evidence appears. After that, your job is to ask why one side is lying, not to repeat the lie and pretend no one knows the truth.
Reposted by Jim Luedtke
Alex Pretti was an ICU nurse serving veterans. He died trying to protect protestors being assaulted. A group of anonymous & masked men fired chemicals into his face, beat him, disarmed him, and shot him in broad daylight in front of witnesses. Then his government smeared him & defended his murder.
January 24, 2026 at 11:44 PM
Alex Pretti was an ICU nurse serving veterans. He died trying to protect protestors being assaulted. A group of anonymous & masked men fired chemicals into his face, beat him, disarmed him, and shot him in broad daylight in front of witnesses. Then his government smeared him & defended his murder.
Reposted by Jim Luedtke
This looks like an execution. There must be an investigation. There must be accountability.
Joining ICE does not give you license to murder.
The President is escalating the situation—and I have no faith he will stop. The Republican Congress must join us to end this. Enough.
Joining ICE does not give you license to murder.
The President is escalating the situation—and I have no faith he will stop. The Republican Congress must join us to end this. Enough.
Live: Man shot and killed by federal agents in Minneapolis this morning, police chief says
A video appears to shows federal agents wrestling a man to the ground then shooting him. The Department of Homeland Security said the man was armed with a gun.
www.startribune.com
January 24, 2026 at 5:58 PM
This looks like an execution. There must be an investigation. There must be accountability.
Joining ICE does not give you license to murder.
The President is escalating the situation—and I have no faith he will stop. The Republican Congress must join us to end this. Enough.
Joining ICE does not give you license to murder.
The President is escalating the situation—and I have no faith he will stop. The Republican Congress must join us to end this. Enough.
Reposted by Jim Luedtke
The last few years have seen the largest wave of immigration in American history. All those images we carry in our heads about people arriving at Ellis Island — we just surpassed that. Crime went down. Real wages went up. This is a fake problem. Enough is enough.
January 24, 2026 at 4:36 PM
The last few years have seen the largest wave of immigration in American history. All those images we carry in our heads about people arriving at Ellis Island — we just surpassed that. Crime went down. Real wages went up. This is a fake problem. Enough is enough.
Reposted by Jim Luedtke
It’s -9 degrees. Downtown Minneapolis is packed for the anti-ICE rally and the crowd keeps growing
January 23, 2026 at 8:16 PM
It’s -9 degrees. Downtown Minneapolis is packed for the anti-ICE rally and the crowd keeps growing
Reposted by Jim Luedtke
Happy to chair this year’s Lifetime Achievement in Location Analysis Award committee with co-chairs Dr. Sibel Alumur Alev (University of Waterloo) and Dr. Rajan Batta (University at Buffalo). Please see the call for nominations and help spread the word!
January 11, 2026 at 8:11 PM
Happy to chair this year’s Lifetime Achievement in Location Analysis Award committee with co-chairs Dr. Sibel Alumur Alev (University of Waterloo) and Dr. Rajan Batta (University at Buffalo). Please see the call for nominations and help spread the word!
Reposted by Jim Luedtke
to turn off autoplaying video on the bluesky mobile app
select the icon in the top left corner
go to settings
go to content and media
make sure "autoplay videos and gifs" is toggled off
select the icon in the top left corner
go to settings
go to content and media
make sure "autoplay videos and gifs" is toggled off
April 18, 2025 at 11:35 PM
to turn off autoplaying video on the bluesky mobile app
select the icon in the top left corner
go to settings
go to content and media
make sure "autoplay videos and gifs" is toggled off
select the icon in the top left corner
go to settings
go to content and media
make sure "autoplay videos and gifs" is toggled off
Reposted by Jim Luedtke
I’m happy to share that I’m starting my term as President of @informs.bsky.social Section on Location Analysis. I look forward to continuing to serve our community, leading SOLA activities, supporting our members, and strengthening the impact of location analysis research and applications.
January 7, 2026 at 6:14 PM
I’m happy to share that I’m starting my term as President of @informs.bsky.social Section on Location Analysis. I look forward to continuing to serve our community, leading SOLA activities, supporting our members, and strengthening the impact of location analysis research and applications.
Reposted by Jim Luedtke
I've written an end of year substack post about tracking Trump, where we are ending the year and some implications for Europe and for me personally...
christinapagel.substack.com/p/personal-r...
christinapagel.substack.com/p/personal-r...
Personal reflections on a Trumpian 2025
The implications of a year in Trump's new America and why I started tracking Trump - and why I'm not stopping.
christinapagel.substack.com
December 29, 2025 at 3:25 PM
I've written an end of year substack post about tracking Trump, where we are ending the year and some implications for Europe and for me personally...
christinapagel.substack.com/p/personal-r...
christinapagel.substack.com/p/personal-r...
Reposted by Jim Luedtke
"Nearly 80 years later, the simplex method is still among the most widely used tools when a logistical or supply-chain decision needs to be made under complex constraints."
only half followed the description of the simplex method in here but super interesting anyways
www.wired.com/story/resear...
only half followed the description of the simplex method in here but super interesting anyways
www.wired.com/story/resear...
Research Reveals the Optimal Way to Optimize
The leading approach to the simplex method, a widely used technique for balancing complex logistical constraints, can’t get any better.
www.wired.com
December 21, 2025 at 12:12 PM
"Nearly 80 years later, the simplex method is still among the most widely used tools when a logistical or supply-chain decision needs to be made under complex constraints."
only half followed the description of the simplex method in here but super interesting anyways
www.wired.com/story/resear...
only half followed the description of the simplex method in here but super interesting anyways
www.wired.com/story/resear...
Reposted by Jim Luedtke
New preprint! 📄 Data-driven convergence guarantees for first-order methods via PEP + Wasserstein DRO.
Less pessimistic probabilistic rates that reflect how your solver actually behaves 🎯
📎 arxiv.org/abs/2511.17834
💻 github.com/stellatogrp/dro_pep
w/ Jisun Park & Vinit Ranjan #optimization #fom
Less pessimistic probabilistic rates that reflect how your solver actually behaves 🎯
📎 arxiv.org/abs/2511.17834
💻 github.com/stellatogrp/dro_pep
w/ Jisun Park & Vinit Ranjan #optimization #fom
December 18, 2025 at 8:38 PM
New preprint! 📄 Data-driven convergence guarantees for first-order methods via PEP + Wasserstein DRO.
Less pessimistic probabilistic rates that reflect how your solver actually behaves 🎯
📎 arxiv.org/abs/2511.17834
💻 github.com/stellatogrp/dro_pep
w/ Jisun Park & Vinit Ranjan #optimization #fom
Less pessimistic probabilistic rates that reflect how your solver actually behaves 🎯
📎 arxiv.org/abs/2511.17834
💻 github.com/stellatogrp/dro_pep
w/ Jisun Park & Vinit Ranjan #optimization #fom
Reposted by Jim Luedtke
Care about gun control?
Climate change?
Gun control?
Abortion rights?
Gun control?
Universal health care?
Gun control?
Higher education funding?
Gun control?
Abolishing ICE?
Gun control?
Ending murder on the high seas?
Gun control?
Etc.
Your platform is <institutional reform>
Climate change?
Gun control?
Abortion rights?
Gun control?
Universal health care?
Gun control?
Higher education funding?
Gun control?
Abolishing ICE?
Gun control?
Ending murder on the high seas?
Gun control?
Etc.
Your platform is <institutional reform>
<Everything> else - whatever Kitchen Table or civil rights or other policy issue you care about - <follows> from fixing our broken institutions & having multiparty majoritarian democracy. <All> of it. We keep doing it backwards, thinking Just One Popular Policy will fix it. It’s a category error.
This is why Democrats need a platform focused on institutional reform. Having to adopt policy positions opposed by supermajorities of the national public to win the hyper-malapportioned Senate is anti-democratic, & promising policies you can never pass is political suicide.
bsky.app/profile/mcop...
bsky.app/profile/mcop...
December 14, 2025 at 4:04 AM
Care about gun control?
Climate change?
Gun control?
Abortion rights?
Gun control?
Universal health care?
Gun control?
Higher education funding?
Gun control?
Abolishing ICE?
Gun control?
Ending murder on the high seas?
Gun control?
Etc.
Your platform is <institutional reform>
Climate change?
Gun control?
Abortion rights?
Gun control?
Universal health care?
Gun control?
Higher education funding?
Gun control?
Abolishing ICE?
Gun control?
Ending murder on the high seas?
Gun control?
Etc.
Your platform is <institutional reform>
Reposted by Jim Luedtke
After 18+ years working for Maplesoft, I was "downsized" on Black Friday and I am currently on the lookout for new opportunities. I will be looking in earnest in the new year, but any leads on math programming/teaching work (especially in Los Angeles) would be appreciated.
December 10, 2025 at 6:41 AM
After 18+ years working for Maplesoft, I was "downsized" on Black Friday and I am currently on the lookout for new opportunities. I will be looking in earnest in the new year, but any leads on math programming/teaching work (especially in Los Angeles) would be appreciated.
Reposted by Jim Luedtke
As newsrooms shutter and paywalls rise elsewhere, public media delivers critical, unbiased reporting without fear or favor. That's the promise of a free press in a democracy.
Click here to support the network of voices that keeps our public conversation honest and informed: n.pr/4pCcFIx
Click here to support the network of voices that keeps our public conversation honest and informed: n.pr/4pCcFIx
December 10, 2025 at 12:34 PM
As newsrooms shutter and paywalls rise elsewhere, public media delivers critical, unbiased reporting without fear or favor. That's the promise of a free press in a democracy.
Click here to support the network of voices that keeps our public conversation honest and informed: n.pr/4pCcFIx
Click here to support the network of voices that keeps our public conversation honest and informed: n.pr/4pCcFIx
Reposted by Jim Luedtke
I’m excited to share the materials from my Stanford seminar course, “AI for Algorithmic Reasoning and Optimization”: vitercik.github.io/ai4algs_25/. It covered formal algorithmic frameworks for analyzing LLM reasoning, GNNs for combinatorial/mathematical optimization, and theoretical guarantees.
December 2, 2025 at 9:55 PM
I’m excited to share the materials from my Stanford seminar course, “AI for Algorithmic Reasoning and Optimization”: vitercik.github.io/ai4algs_25/. It covered formal algorithmic frameworks for analyzing LLM reasoning, GNNs for combinatorial/mathematical optimization, and theoretical guarantees.
Reposted by Jim Luedtke
⚠️ WANTED: PhD student ⚠️
The topic? GPU-friendly algorithms for discrete optimization and mathematical programming, to be used inside decision-focused learning pipelines.
The mentors? My colleague Axel Parmentier and myself.
[1/3]
The topic? GPU-friendly algorithms for discrete optimization and mathematical programming, to be used inside decision-focused learning pipelines.
The mentors? My colleague Axel Parmentier and myself.
[1/3]
November 21, 2025 at 4:52 PM
⚠️ WANTED: PhD student ⚠️
The topic? GPU-friendly algorithms for discrete optimization and mathematical programming, to be used inside decision-focused learning pipelines.
The mentors? My colleague Axel Parmentier and myself.
[1/3]
The topic? GPU-friendly algorithms for discrete optimization and mathematical programming, to be used inside decision-focused learning pipelines.
The mentors? My colleague Axel Parmentier and myself.
[1/3]
Reposted by Jim Luedtke
Along with advancing optimization and game-theory research for post-disaster aid, Prof. Michini’s NSF CAREER Award supports new courses and researcher visits to help students learn the field: “I want to break that barrier…between professors and students..."🔗go.wisc.edu/zeuiau
@uwmadison.bsky.social
@uwmadison.bsky.social
Michini will use CAREER Award to improve post-disaster aid operations and more - College of Engineering - University of Wisconsin-Madison
While Carla Michini and her family took their usual summer trip to her native Italy in 2025, this was no relaxing getaway. Michini, an assistant professor of industrial and systems engineering at the University of...
go.wisc.edu
November 18, 2025 at 4:00 PM
Along with advancing optimization and game-theory research for post-disaster aid, Prof. Michini’s NSF CAREER Award supports new courses and researcher visits to help students learn the field: “I want to break that barrier…between professors and students..."🔗go.wisc.edu/zeuiau
@uwmadison.bsky.social
@uwmadison.bsky.social
Reposted by Jim Luedtke
Lately, I have been obsessed with developing theoretically based optimization algorithms that actually attain the best practical performance.
Alas, the classic model of minimax optimal methods is overly conservative; it overfits to tune its worst-case.
We found a path forward 1/
Alas, the classic model of minimax optimal methods is overly conservative; it overfits to tune its worst-case.
We found a path forward 1/
November 18, 2025 at 2:59 PM
Lately, I have been obsessed with developing theoretically based optimization algorithms that actually attain the best practical performance.
Alas, the classic model of minimax optimal methods is overly conservative; it overfits to tune its worst-case.
We found a path forward 1/
Alas, the classic model of minimax optimal methods is overly conservative; it overfits to tune its worst-case.
We found a path forward 1/
Reposted by Jim Luedtke
Alberto Del Pia
Projection-width: a unifying structural parameter for separable discrete optimization
https://arxiv.org/abs/2511.02990
Projection-width: a unifying structural parameter for separable discrete optimization
https://arxiv.org/abs/2511.02990
November 6, 2025 at 6:54 AM
Alberto Del Pia
Projection-width: a unifying structural parameter for separable discrete optimization
https://arxiv.org/abs/2511.02990
Projection-width: a unifying structural parameter for separable discrete optimization
https://arxiv.org/abs/2511.02990
Reposted by Jim Luedtke
October 29, 2025 at 4:29 AM
Reposted by Jim Luedtke
The simplex algorithm is super efficient. 80 years of experience says it runs in linear time. Nobody can explain _why_ it is so fast.
We invented a new algorithm analysis framework to find out.
We invented a new algorithm analysis framework to find out.
Beyond Smoothed Analysis: Analyzing the Simplex Method by the Book
Narrowing the gap between theory and practice is a longstanding goal of the algorithm analysis community. To further progress our understanding of how algorithms work in practice, we propose a new alg...
arxiv.org
October 27, 2025 at 1:43 AM
The simplex algorithm is super efficient. 80 years of experience says it runs in linear time. Nobody can explain _why_ it is so fast.
We invented a new algorithm analysis framework to find out.
We invented a new algorithm analysis framework to find out.
Reposted by Jim Luedtke
Any serious future for democracy in America requires us to get rid of single-member districts. It is the only long-term solution to this nonsense.
October 22, 2025 at 3:42 PM
Any serious future for democracy in America requires us to get rid of single-member districts. It is the only long-term solution to this nonsense.