25,161
edits
Changes
Created page with "'''Home * People * Jens Christensen''' FILE:JensChristensenPhD.jpg|border|right|thumb|link=https://www.linkedin.com/in/jensbchristensen/| Jens Christensen..."
'''[[Main Page|Home]] * [[People]] * Jens Christensen'''
[[FILE:JensChristensenPhD.jpg|border|right|thumb|link=https://www.linkedin.com/in/jensbchristensen/| Jens Christensen <ref>[https://www.linkedin.com/in/jensbchristensen/ Jens Christensen | LinkedIn]</ref> ]]
'''Jens Christensen''',<br/>
an American computer scientist, [[Artificial Intelligence|AI]]-researcher and entrepreneur, Ph.D. from [[Stanford University]] in 1991 on automatic abstraction in [[Planning|planning]] <ref>[[Jens Christensen]] ('''1991'''). ''Automatic Abstraction in Planning''. Ph.D. thesis, [[Stanford University]], [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970034976.pdf pdf]</ref>.
Along with [[Richard Korf]], he elaborated on a ''Unified Theory of Heuristic Evaluation functions and Its Applications to Learning'' on [[Automated Tuning|optimization]] of feature weights by [[Hill Climbing|hill climbing]] methods and [[Automated Tuning#LinearRegression|linear regression]].
In one experiment, a set of [[Point Value|relative weights]] for different [[Pieces|chess pieces]] was automatically [[Learning|learned]].
=Experiments with Chess=
<span id="Experiments"></span>Excerpt from ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' <ref>[[Jens Christensen]], [[Richard Korf]] ('''1986'''). ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' [[Conferences#AAAI-86|AAAI-86]], [http://www.aaai.org/Papers/AAAI/1986/AAAI86-023.pdf pdf]</ref>:
As a serious test, we chose the game of chess and a simple evaluation function consisting only of [[Material|material]] advantage. The experiment was to see if the learning program would approximate the classically accepted [[Point Value|weights]] for the pieces: 9 for the queen, 5 for the rook, 3 for the bishop, 3 for the knight, and 1 for the pawn.
The chess program was implemented using a two-ply mini-max search with [[Alpha-Beta|alpha-beta pruning]] and [[Quiescence Search|quiescence]]. 1400 half moves were made between each regression. If neither side won during a game it was stopped after 100 half-moves and a new game was started. For purposes of the experiment, a win was assigned one more than the total initial material value, and the individual piece values were rounded off to the nearest 0.5. The pieces stabilized at: Queen, 8.0; rook, 4.0; bishop, 4.0; knight, 3.0; pawn 2.0. ...
=Selected Publications=
<ref>[https://dblp.uni-trier.de/pers/hd/c/Christensen:Jens.html dblp: Jens Christensen]</ref>
* [[Jens Christensen]], [[Richard Korf]] ('''1986'''). ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' [[Conferences#AAAI-86|AAAI-86]], [http://www.aaai.org/Papers/AAAI/1986/AAAI86-023.pdf pdf]
* [[Jens Christensen]] ('''1986'''). ''[https://link.springer.com/chapter/10.1007%2F978-1-4613-2279-5_9 Learning Static Evaluation Functions by Linear Regression]''. in [[Tom Mitchell]], [[Jaime Carbonell]], [[Ryszard Michalski]] ('''1986'''). ''[https://link.springer.com/book/10.1007/978-1-4613-2279-5 Machine Learning: A Guide to Current Research]''. The Kluwer International Series in Engineering and Computer Science, Vol. 12
* [[Jens Christensen]] ('''1990'''). ''A Hierarchical Planner that Generates Its Own Hierarchies''. [[Conferences#AAAI-90|AAAI-90]], [https://www.aaai.org/Papers/AAAI/1990/AAAI90-150.pdf pdf]
* [[Jens Christensen]], [https://dblp.uni-trier.de/pers/hd/g/Grove:Adam_J=.html Adam Grove] ('''1991'''). ''A Formal Model Classical Planning''. [[Conferences#IJCAI1991|IJCAI 91]], [https://www.ijcai.org/Proceedings/91-1/Papers/039.pdf pdf]
* [[Jens Christensen]] ('''1991'''). ''Automatic Abstraction in Planning''. Ph.D. thesis, [[Stanford University]], [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970034976.pdf pdf]
=External Links=
* [https://www.linkedin.com/in/jensbchristensen/ Jens Christensen | LinkedIn]
* [https://www.brulteco.com/jens-christensen-innovation-interview/ Jens Christensen: The Innovation Interview | Brulte & Company], September 8, 2014
=References=
<references />
'''[[People|Up one level]]'''
[[Category:Researcher|Christensen]]
[[Category:Entrepreneur|Christensen]]
[[FILE:JensChristensenPhD.jpg|border|right|thumb|link=https://www.linkedin.com/in/jensbchristensen/| Jens Christensen <ref>[https://www.linkedin.com/in/jensbchristensen/ Jens Christensen | LinkedIn]</ref> ]]
'''Jens Christensen''',<br/>
an American computer scientist, [[Artificial Intelligence|AI]]-researcher and entrepreneur, Ph.D. from [[Stanford University]] in 1991 on automatic abstraction in [[Planning|planning]] <ref>[[Jens Christensen]] ('''1991'''). ''Automatic Abstraction in Planning''. Ph.D. thesis, [[Stanford University]], [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970034976.pdf pdf]</ref>.
Along with [[Richard Korf]], he elaborated on a ''Unified Theory of Heuristic Evaluation functions and Its Applications to Learning'' on [[Automated Tuning|optimization]] of feature weights by [[Hill Climbing|hill climbing]] methods and [[Automated Tuning#LinearRegression|linear regression]].
In one experiment, a set of [[Point Value|relative weights]] for different [[Pieces|chess pieces]] was automatically [[Learning|learned]].
=Experiments with Chess=
<span id="Experiments"></span>Excerpt from ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' <ref>[[Jens Christensen]], [[Richard Korf]] ('''1986'''). ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' [[Conferences#AAAI-86|AAAI-86]], [http://www.aaai.org/Papers/AAAI/1986/AAAI86-023.pdf pdf]</ref>:
As a serious test, we chose the game of chess and a simple evaluation function consisting only of [[Material|material]] advantage. The experiment was to see if the learning program would approximate the classically accepted [[Point Value|weights]] for the pieces: 9 for the queen, 5 for the rook, 3 for the bishop, 3 for the knight, and 1 for the pawn.
The chess program was implemented using a two-ply mini-max search with [[Alpha-Beta|alpha-beta pruning]] and [[Quiescence Search|quiescence]]. 1400 half moves were made between each regression. If neither side won during a game it was stopped after 100 half-moves and a new game was started. For purposes of the experiment, a win was assigned one more than the total initial material value, and the individual piece values were rounded off to the nearest 0.5. The pieces stabilized at: Queen, 8.0; rook, 4.0; bishop, 4.0; knight, 3.0; pawn 2.0. ...
=Selected Publications=
<ref>[https://dblp.uni-trier.de/pers/hd/c/Christensen:Jens.html dblp: Jens Christensen]</ref>
* [[Jens Christensen]], [[Richard Korf]] ('''1986'''). ''A Unified Theory of Heuristic Evaluation functions and Its Applications to Learning.'' [[Conferences#AAAI-86|AAAI-86]], [http://www.aaai.org/Papers/AAAI/1986/AAAI86-023.pdf pdf]
* [[Jens Christensen]] ('''1986'''). ''[https://link.springer.com/chapter/10.1007%2F978-1-4613-2279-5_9 Learning Static Evaluation Functions by Linear Regression]''. in [[Tom Mitchell]], [[Jaime Carbonell]], [[Ryszard Michalski]] ('''1986'''). ''[https://link.springer.com/book/10.1007/978-1-4613-2279-5 Machine Learning: A Guide to Current Research]''. The Kluwer International Series in Engineering and Computer Science, Vol. 12
* [[Jens Christensen]] ('''1990'''). ''A Hierarchical Planner that Generates Its Own Hierarchies''. [[Conferences#AAAI-90|AAAI-90]], [https://www.aaai.org/Papers/AAAI/1990/AAAI90-150.pdf pdf]
* [[Jens Christensen]], [https://dblp.uni-trier.de/pers/hd/g/Grove:Adam_J=.html Adam Grove] ('''1991'''). ''A Formal Model Classical Planning''. [[Conferences#IJCAI1991|IJCAI 91]], [https://www.ijcai.org/Proceedings/91-1/Papers/039.pdf pdf]
* [[Jens Christensen]] ('''1991'''). ''Automatic Abstraction in Planning''. Ph.D. thesis, [[Stanford University]], [https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970034976.pdf pdf]
=External Links=
* [https://www.linkedin.com/in/jensbchristensen/ Jens Christensen | LinkedIn]
* [https://www.brulteco.com/jens-christensen-innovation-interview/ Jens Christensen: The Innovation Interview | Brulte & Company], September 8, 2014
=References=
<references />
'''[[People|Up one level]]'''
[[Category:Researcher|Christensen]]
[[Category:Entrepreneur|Christensen]]
