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PRODID:-//Biomedical Mathematics Group - ECPv6.15.20//NONSGML v1.0//EN
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X-WR-CALDESC:Events for Biomedical Mathematics Group
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TZID:Asia/Seoul
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TZOFFSETFROM:+0900
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DTSTART:20200101T000000
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DTSTART;TZID=Asia/Seoul:20211118T130000
DTEND;TZID=Asia/Seoul:20211118T140000
DTSTAMP:20260427T090915
CREATED:20211117T190000Z
LAST-MODIFIED:20211101T080821Z
UID:5187-1637240400-1637244000@www.ibs.re.kr
SUMMARY:Solving Singular Control Problems in Mathematical Biology\, Using PASA
DESCRIPTION:We will discuss about “Solving Singular Control Problems in Mathematical Biology\, Using PASA”\, Atkins et al.\, arXiv\, 2020 \nIn this paper\, we will demonstrate how to use a nonlinear polyhedral constrained optimization solver called the Polyhedral Active Set Algorithm (PASA) for solving a general singular control problem. We present methods of discretizing a general optimal control problem that involves the use of the gradient of the Lagrangian for computing the gradient of the cost functional so that PASA can be applied. When a numerical solution contains artifacts that resemble “chattering”\, a phenomenon where the control oscillates wildly along the singular region\, we recommend a method of regularizing the singular control problem by adding a term to the cost functional that measures a scalar multiple of the total variation of the control\, where the scalar is viewed as a tuning parameter. We then demonstrate PASA’s performance on three singular control problems that give rise to different applications of mathematical biology. We also provide some exposition on the heuristics that we use in determining an appropriate size for the tuning parameter.
URL:https://www.ibs.re.kr/bimag/event/2021-11-18-2/
LOCATION:B378 Seminar room\, IBS\, 55 Expo-ro Yuseong-gu\, Daejeon\, 34126\, Korea\, Republic of
CATEGORIES:Journal Club
ORGANIZER;CN="Jae Kyoung Kim":MAILTO:jaekkim@kaist.ac.kr
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