This Article 
 Bibliographic References 
 Add to: 
L'Hôpital's Filter for QSIM
January 1998 (vol. 20 no. 1)
pp. 1-8

Abstract—We have identified a source of spurious predictions inside the qualitative simulation algorithm QSIM. The algorithm fails to check for violations of l'Hôpital's rule, which causes the addition of inconsistent states to the behavior tree. Our proposed solution involves adding a new state filter to make the required controls and does not necessitate any additions or restrictions in the input set. We make use of extended corresponding value tuples spanning multiple constraints. The necessary modifications to the algorithm are explained and the technique is demonstrated on examples. Used in conjunction with other spurious behavior elimination methods, this approach would increase QSIM's ability to handle more complex systems.

[1] P. Fouché and B.J. Kuipers, "Reasoning About Energy in Qualitative Simulation," IEEE Trans. Systems, Man, and Cybernetics, vol. 22, pp. 47-63, 1992.
[2] B.J. Kuipers, "Qualitative Simulation," Artificial Intelligence, vol. 29, pp. 289-338, 1986.
[3] B.J. Kuipers, Qualitative Reasoning: Modeling and Simulation With Incomplete Knowledge.Cambridge, Mass.: MIT Press, 1994.
[4] B.J. Kuipers and D. Berleant, "A Smooth Integration of Incomplete Quantitative Knowledge Into Qualitative Simulation," Univ. of Texas at Austin, Artificial Intelligence Lab., AI TR 90-122, 1990.
[5] B.J. Kuipers, C. Chiu, D.T. Dalle Molle, and D.R. Throop, "Higher-Order Derivative Constraints in Qualitative Simulation," Artificial Intelligence, vol. 51, pp. 343-379, 1991.
[6] W.W. Lee and B.J. Kuipers, "Non-Intersection of Trajectories in Qualitative Phase Space: A Global Constraint for Qualitative Simulation," Proc. Seventh Nat'l Conf. Artificial Intelligence, pp. 286-291,Los Altos, Calif., 1988.
[7] A.C.C. Say, "Limitations Imposed by the Sign-Equality Assumption in Qualitative Simulation," Proc. 11th Int'l Workshop Qualitative Reasoning, pp. 165-173,Cortona, Italy, June 1997.
[8] A.C.C. Say, "Numbers Representable in Pure QSIM," Proc. Eleventh Int'l Workshop Qualitative Reasoning, pp. 337-344,Cortona, Italy, June 1997.
[9] A.C.C. Say and S. Kuru, “Improved Filtering for the QSIM Algorithm,” IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 15, pp. 967-971, 1993.
[10] G.B. Thomas, Jr. and R.L. Finney, Calculus and Analytic Geometry, fifth ed. Reading, Mass.: Addison-Wesley, 1983.
[11] B.C. Williams, "A Theory of Interactions: Unifying Qualitative and Quantitative Algebraic Reasoning," Artificial Intelligence, vol. 51, pp. 39-94, 1991.

Index Terms:
Qualitative reasoning, qualitative simulation, spurious behaviors, QSIM, state filtering.
A.c. Cem Say, "L'Hôpital's Filter for QSIM," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 20, no. 1, pp. 1-8, Jan. 1998, doi:10.1109/34.655645
Usage of this product signifies your acceptance of the Terms of Use.