{"type":"ScholarlyArticle","title":"Combining Discrete and Continuous Process Models","authors":[{"name":"Daniel S. Weld","slug":"daniel-s-weld","given":"Daniel S.","family":"Weld","affiliation":""}],"abstract":"Two notions of process have been used in programs that reason about change: discrete models, which represe nt changes as instantaneous, and con tinuou s models, which represent changes as processes th at act gradually over tim e. We desc ribe a tec hnique calleLi aggregation wh ich unili es the two types of models and allows both to be used when performing qualitative simulation . Aggregation is a technique f or recognizing cyc les of processes and generating a continuous process that is equivalen t to each cyc l e. A qualitative simul ator may start pr ed ictio n with a simple di sc rete model and use aggregation to generate a continuo us process model when discrete simulation bogs down in a cycle. Ag \\Jregation thereby all ows a simu lator to switc h back and forth between differen t types of models depending on which type is most exped ient. To test these ideas, we have written a progra m, PEPTIDE, wh ich performs qualitative simulatio n in the domain of molecular genetics. The fl exibi lity of PEPTIDE 's agg regator allows the program to detec t cyc les wi thin cyc les and predict th e behavior of comp lex situations.","doi":null,"url":"https://ijcai.org/proceedings/1985/25","pdf":"https://ijcai.org/proceedings/1985/0025.pdf","markdown":"https://ijcai.org/proceedings/1985/25.md","bibtex":"https://ijcai.org/proceedings/1985/bibtex/25","volume":{"slug":"1985","title":"Proceedings of the Ninth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 1985","url":"https://ijcai.org/proceedings/1985/","year":1985,"location":"Los Angeles, California, USA","dates":"","editors":"Aravind Joshi","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Automated Reasoning","track":"Automated Reasoning","number":25,"pages":{"first":140,"last":142},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}