Rick Valenzano (@RickValenzano) profile picture

Assistant Professor at Toronto Metropolitan University. General admirer of sport, music, film, and whimsy.

Toronto, Ontario
Joined November 2011
Photo by Rick Valenzano (@RickValenzano)Photo by Rick Valenzano (@RickValenzano)Photo by Rick Valenzano (@RickValenzano)Photo by Rick Valenzano (@RickValenzano)
We cover topics such as automated planning, search methods, experimental design, etc. Could be interesting to a variety of @CompSciGradTMU students, as well as @FEAStorontometu students, especially those doing robotics, optimization, and operations research
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I was evacuated from #Jasper while camping with my husband and two young kids this week. This is my #jasperwildfire story. We arrived at Wabasso campground Sunday afternoon. It was 34 degrees, and the man at the check in booth was sweating profusely in the heat. He (1/22)
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This year we are happy to announce two recipients of the CAIAC Lifetime Achievement Award: Dr. Sheila McIlraith (U. Toronto) and Dr. Ghorbani Ali (U. New Brunswick). These awards recognize outstanding research excellence in AI throughout their careers. caiac.ca/en/lifetime-achieve…
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Excited to again be teaching my grad course on Heuristic Search at @TMU_CS . If you are interested, you can find more info at bit.ly/41WV4Av @TMUgraduate @TorontoMetSci @CompSciGradTMU Could also be interesting for Operations Research students in @FEAStorontometu
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I am looking for MSc and PhD students to join my team! If you are interested in heuristic search, planning, and the intersection of these topics in RL, consider applying at torontomu.ca/cs/graduate/ . More information about me at cs.torontomu.ca/~rick.valenz…
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There are some differences in setting. Dijkstra finds a path from an input s to ALL other vertices, whereas A* focuses on finding one path from s to a single vertex (typically). This is why the A* work focuses on "must expand" vertices.
Replying to @thesasho
This was first shown by Dechter and Pearl in 1985. There is more recent work by @nathansttt et al. that I think cleans it up a bit and extends the result to bi-directional search.
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And says nothing about those with an evaluation equal to the length of the optimal path. The A*-based work also typically assumes a "consistent" heuristic, which is a triangle inequality on how the heuristic function changes from vertex to vertex
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But the "heuristic used by Dijkstra's" satisfies that condition. The bi-directional paper is here: webdocs.cs.ualberta.ca/~nath… The 1985 paper is here: dl.acm.org/doi/10.1145/3828.…
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Interesting. I am going to have to take a look. I'm curious how it extends to A*, for which we know that any "equally informed" algorithm B (ie. with the same heuristic), A* will be at least as fast as B (aside from tie-breaking). Dijkstra's after all is just A* with no heuristic
This looks really cool! With the right priority queue, Dijkstra's algorithm is universally optimal: for any graph G and any other algorithm A, there exist weights on the graph edges for which A would make at least as many comparisons as Dijkstra's.
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Thrilled to announce that our JAIR paper on Reward Machines (jair.org/index.php/jair/arti…) has won the 2023 IJCAI-JAIR Best Paper Prize @IJCAIconf @JAIR_Editor Joint work with @RToroIcarte Toryn Klassen and @SheilaMcIlraith
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Excited to announce our paper on Learning Reward Machines from experience for partially observable reinforcement learning has been published as a pre-proof in AIJ. Work with @RToroIcarte @mcilraith and other : doi.org/10.1016/j.artint.202…
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We are still accepting grad applications at @TMU_CS for Canadian students. I myself have a few positions open for people interested in heuristic search, planning, and combining those topics with RL. Check out my work at rickvalenzano.com if you are interested!
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Looking forward to again be teaching a grad class on Heuristic Search and AI at @TorontoMet . If you are a student interested in attending, you can find out more at bit.ly/3bZRzUj @CompSciGradTMU
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The impressive deep pattern recognition abilities of #DNN's such as #LLM's are sometimes confused for reasoning abilities I can learn to guess, with high accuracy, whether a SAT instance is satisfiable or not, but this not the same as knowing how to solve SAT. Let me explain. 1/
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Rick Valenzano retweeted
The 2024 @ICAPSConference was announced today to be in Banff, BC, Canada. Artwork already found on the lab whiteboard... MuLab will be there to represent!
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Ryerson CS is still accepting PhD and MSc applications for Canadian students (including PRs). I am still looking for PhD students to work on heuristic search, planning, or the intersection of those topics and RL. Please reach out if you are interested!
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This multi-phase conference reviewing is nice in some ways. The downside, is post-rebuttal, I have to remember all the details of a paper I read like two months ago.
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Probably doesn't help to be reviewing for multiple conferences at once and thus trying to keep the details of all these papers in my head simultaneously