{"title":"通过事故后观测确定扩散方程和波动方程中的源项:唯一性和稳定性","authors":"Jin Cheng, Shuai Lu, Masahiro Yamamoto","doi":"10.4208/csiam-am.so-2022-0028","DOIUrl":null,"url":null,"abstract":"We consider a diffusion and a wave equations: $$ \\partial_t^ku(x,t) = \\Delta u(x,t) + \\mu(t)f(x), \\quad x\\in \\Omega, \\, t>0, \\quad k=1,2 $$ with the zero initial and boundary conditions, where $\\Omega \\subset \\mathbb{R}^d$ is a bounded domain. We establish uniqueness and/or stability results for inverse problems of 1. determining $\\mu(t)$, $0<t<T$ with given $f(x)$; 2. determining $f(x)$, $x\\in \\Omega$ with given $\\mu(t)$ \\end{itemize} by data of $u$: $u(x_0,\\cdot)$ with fixed point $x_0\\in \\Omega$ or Neumann data on subboundary over time interval. In our inverse problems, data are taken over time interval $T_1<t<T_1$, by assuming that $T<T_1<T_2$ and $\\mu(t)=0$ for $t\\ge T$, which means that the source stops to be active after the time $T$ and the observations are started only after $T$. This assumption is practical by such a posteriori data after incidents, although inverse problems had been well studied in the case of $T=0$. We establish the non-uniqueness, the uniqueness and conditional stability for a diffusion and a wave equations. The proofs are based on eigenfunction expansions of the solutions $u(x,t)$, and we rely on various knowledge of the generalized Weierstrass theorem on polynomial approximation, almost periodic functions, Carleman estimate, non-harmonic Fourier series.","PeriodicalId":1,"journal":{"name":"Accounts of Chemical Research","volume":null,"pages":null},"PeriodicalIF":16.4000,"publicationDate":"2021-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Determination of Source Terms in Diffusion and Wave Equations by Observations After Incidents: Uniqueness and Stability\",\"authors\":\"Jin Cheng, Shuai Lu, Masahiro Yamamoto\",\"doi\":\"10.4208/csiam-am.so-2022-0028\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We consider a diffusion and a wave equations: $$ \\\\partial_t^ku(x,t) = \\\\Delta u(x,t) + \\\\mu(t)f(x), \\\\quad x\\\\in \\\\Omega, \\\\, t>0, \\\\quad k=1,2 $$ with the zero initial and boundary conditions, where $\\\\Omega \\\\subset \\\\mathbb{R}^d$ is a bounded domain. We establish uniqueness and/or stability results for inverse problems of 1. determining $\\\\mu(t)$, $0<t<T$ with given $f(x)$; 2. determining $f(x)$, $x\\\\in \\\\Omega$ with given $\\\\mu(t)$ \\\\end{itemize} by data of $u$: $u(x_0,\\\\cdot)$ with fixed point $x_0\\\\in \\\\Omega$ or Neumann data on subboundary over time interval. In our inverse problems, data are taken over time interval $T_1<t<T_1$, by assuming that $T<T_1<T_2$ and $\\\\mu(t)=0$ for $t\\\\ge T$, which means that the source stops to be active after the time $T$ and the observations are started only after $T$. This assumption is practical by such a posteriori data after incidents, although inverse problems had been well studied in the case of $T=0$. We establish the non-uniqueness, the uniqueness and conditional stability for a diffusion and a wave equations. The proofs are based on eigenfunction expansions of the solutions $u(x,t)$, and we rely on various knowledge of the generalized Weierstrass theorem on polynomial approximation, almost periodic functions, Carleman estimate, non-harmonic Fourier series.\",\"PeriodicalId\":1,\"journal\":{\"name\":\"Accounts of Chemical Research\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":16.4000,\"publicationDate\":\"2021-07-17\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Accounts of Chemical Research\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4208/csiam-am.so-2022-0028\",\"RegionNum\":1,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Accounts of Chemical Research","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4208/csiam-am.so-2022-0028","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Determination of Source Terms in Diffusion and Wave Equations by Observations After Incidents: Uniqueness and Stability
We consider a diffusion and a wave equations: $$ \partial_t^ku(x,t) = \Delta u(x,t) + \mu(t)f(x), \quad x\in \Omega, \, t>0, \quad k=1,2 $$ with the zero initial and boundary conditions, where $\Omega \subset \mathbb{R}^d$ is a bounded domain. We establish uniqueness and/or stability results for inverse problems of 1. determining $\mu(t)$, $0
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Accounts of Chemical Research presents short, concise and critical articles offering easy-to-read overviews of basic research and applications in all areas of chemistry and biochemistry. These short reviews focus on research from the author’s own laboratory and are designed to teach the reader about a research project. In addition, Accounts of Chemical Research publishes commentaries that give an informed opinion on a current research problem. Special Issues online are devoted to a single topic of unusual activity and significance.
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