| 1. Identificação | |
| Tipo de Referência | Resumo em Evento (Conference Proceedings) |
| Código do Detentor | isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S |
| Site | mtc-m16b.sid.inpe.br (namespace prefix: upn:K28A8B) |
| Identificador | 6qtX3pFwXQZGivnK2Y/Ra7Ru |
| Repositório | sid.inpe.br/mtc-m17@80/2007/08.15.13.52 |
| Última Atualização | 2018:09.21.12.27.06 (UTC) simone |
| Repositório de Metadados | sid.inpe.br/mtc-m17@80/2007/08.15.13.52.39 |
| Última Atualização dos Metadados | 2018:09.21.12.27.08 (UTC) simone |
| Chave Secundária | INPE--PRE/ |
| Chave de Citação | NowosadCampClae:1991:FrFiDi |
| Título | Frequence Filter with Discrete Fourier Transform in the Time Initialization of a Meteorological Model  |
| Ano | 1991 |
| Data de Acesso | 25 ago. 2026 |
| Tipo Secundário | PRE CN |
| Número de Arquivos | 1 |
| Tamanho | 308 KiB |
| 2. Contextualização | |
| Autor | 1 Nowosad, Alexandre Guirland 2 Campos Velho, Haroldo Fraga de 3 Claeyssen, J. C. R. |
| Grupo | 1 CRN-INPE-BR 2 LAC-INPE-BR |
| Afiliação | 1 Instituto Nacional de Pesquisas Espaciais (INPE) 2 Instituto Nacional de Pesquisas Espaciais (INPE) |
| Nome do Evento | Congresso Nacional de Matemática Aplicada e Computacional, 14 (CNMAC). |
| Localização do Evento | Nova Friburgo, RJ |
| Editora (Publisher) | Sociedade Brasileira de Matemática Aplicada e Computacional |
| Cidade da Editora | Rio de Janeiro, RJ |
| Páginas | 139 |
| Título do Livro | Resumos |
| Acervo Hospedeiro | cptec.inpe.br/walmeida/2003/04.25.17.12 upn:K28A8B |
| Histórico (UTC) | 2007-08-15 13:52:39 :: rosemary -> administrator :: 2018-09-21 12:26:46 :: administrator -> simone :: 1991 |
| 3. Conteúdo e estrutura | |
| É a matriz ou uma cópia? | é a matriz |
| Estágio do Conteúdo | concluido |
| Transferível | 1 |
| Tipo do Conteúdo | External Contribution |
| Tipo de Versão | publisher |
| Palavras-Chave | Frequency filter Fourier transform Meteorological models ENGINEERING |
| Resumo | ABSTRACT: Certain types of finite-difference approximations for time derivatives have traditionally been used for integrating hydrodynamical equations because of their know damping properties. For meteorological models, we have a multiple scale presence of high-frequency gravity waves and slow Rossby waves, which difficulties the successfull development of numerical forecasting. Tha Laplace transform technique was suggested as a method for initialization and integration, which consists in the projection of the model equations in the complex plane where a contour, approximated by an inscribed polygon, specify a critic frequence. A backward projection to the real physical space gives an initial state with efficient attenuated high frequencies. This method was also used in the time-integration of a baroclinic model. The permanent filter properties has the benefit of allowing a time step which is sensible larger than the classical time-differencing schemes. In this work, we apply the impulse invariance transformation to the operational equation of a given equation and sample its solution at M points in a convenient way. We then reconstruct a filtered initial data by iterating it with the inverse Fourier discrete transform. It is made, in such a way that the r-th iterate of the solution at the origen is just the Fourier matrix times a filter G and a transform of the linear part times earlier iterate minus the initial non-linear contribution. The filter G eliminates frequencies outside the bands $ [0, \nu ]$ , $ [M - \nu, M - 1]$ with $ \nu$ equal M times desired cutoff frequency $ f_s$ . This filter is sharper than the one used with the Laplace transform and there is no phase alteration. By considering the first harmonic, we could easily choose a cutoff frequency of the solution spectrum in such a way that the transfer function of the linear part of the system vanishes for high frequencies. Then to approximate the solution by a linear combination of sino functions. We expect that this method confirms numerical experiments which are on the way.. |
| Área | CEA |
| Arranjo 1 | urlib.net > BDMCI > Fonds > Produção anterior à 2021 > LABAC > Frequence Filter with... |
| Arranjo 2 | urlib.net > BDMCI > Fonds > Produção anterior à 2021 > CRCRN > Frequence Filter with... |
| Conteúdo da Pasta doc | acessar |
| Conteúdo da Pasta source | não têm arquivos |
| Conteúdo da Pasta agreement | não têm arquivos |
| 4. Condições de acesso e uso | |
| URI dos dados | upn:K28A8B:6qtX3pFwXQZGivnK2Y/Ra7Ru |
| URL dos dados | http://urlib.net/ibi/6qtX3pFwXQZGivnK2Y/Ra7Ru |
| URL dos dados zipados | http://urlib.net/zip/6qtX3pFwXQZGivnK2Y/Ra7Ru |
| Idioma | en |
| Arquivo Alvo | Nowosad_frequence.pdf |
| Grupo de Usuários | administrator rosemary administrator |
| Grupo de Leitores | administrator simone |
| Visibilidade | shown |
| Permissão de Atualização | não transferida |
| 5. Fontes relacionadas | |
| Unidades Imediatamente Superiores | 8JMKD3MGPCW/3ESGTTP 8JMKD3MGPCW/3EUAPES |
| Lista de Itens Citando | sid.inpe.br/bibdigital/2013/10.03.20.46 - 52 sid.inpe.br/bibdigital/2013/09.22.23.14 - 28 sid.inpe.br/bibdigital@80/2006/04.07.15.50.13 - 5 |
| 6. Notas | |
| Campos Vazios | archivingpolicy archivist callnumber copyholder copyright creatorhistory date descriptionlevel dissemination doi e-mailaddress edition editor electronicmailaddress format isbn issn label lineage mark mirrorrepository nextedition notes numberofvolumes orcid organization parameterlist parentrepositories previousedition previouslowerunit progress project readpermission resumeid rightsholder schedulinginformation secondarydate secondarymark serieseditor session shorttitle sponsor subject tertiarymark tertiarytype type url volume |
| 7. Controle da descrição | |
| e-Mail (login) | simone |
| atualizar | |