Pub Date : 2022-08-11DOI: 10.29215/pecen.v6i1.1873
Ana Paula, D. Vigo
O presente trabalho apresenta um estudo aplicado a problemas modelados por leis de conserva-ção, com condições iniciais e de contorno apropriadas. Em particular, abordaremos a aplicação de métodos limitadores com ênfase no método limitador de inclinação na solução das equações de águas rasas no caso linear e não linear. Apresentamos através de exemplos numéricos um estudo comparativo do comportamento de diferentes funções limitadoras.
{"title":"Aplicação do método de limitadores de inclinação para leis de conservação - Equações de águas rasas","authors":"Ana Paula, D. Vigo","doi":"10.29215/pecen.v6i1.1873","DOIUrl":"https://doi.org/10.29215/pecen.v6i1.1873","url":null,"abstract":"O presente trabalho apresenta um estudo aplicado a problemas modelados por leis de conserva-ção, com condições iniciais e de contorno apropriadas. Em particular, abordaremos a aplicação de métodos limitadores com ênfase no método limitador de inclinação na solução das equações de águas rasas no caso linear e não linear. Apresentamos através de exemplos numéricos um estudo comparativo do comportamento de diferentes funções limitadoras.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":"87 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76849282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-11DOI: 10.29215/pecen.v6i1.1872
Anna Carolina Da Silva Calheiros De Mendonça
Este artigo apresenta um estudo preliminar sobre as relações entre atividades docentes, a raça dos docentes e o Índice Geral de Cursos (IGC), o principal indicador de qualidade do ensino superior. Para isso, três modelos de regressão linear múltipla foram estimados, acompanhados de uma análise descritiva. Os resultados indicam a importância da participação em pesquisa e da bolsa de pesquisa para o aumento do indicador. Políticas de apoio a atividades docentes além do ensino podem resultar em maior capacitação de professores e alunos. Do ponto de vista de equidade, o aumento da proporção de docentes brancos melhora o IGC, enquanto o aumento de docentes pardos gera uma piora no índice. Isso aponta para a necessidade de estudos mais profundos sobre a equidade docente no ensino superior.
{"title":"Avaliação das instituições de Ensino Superior a partir de dados do Instituto Nacional de Estudos e Pesquisas Educacionais Anísio Teixeira (INEP)","authors":"Anna Carolina Da Silva Calheiros De Mendonça","doi":"10.29215/pecen.v6i1.1872","DOIUrl":"https://doi.org/10.29215/pecen.v6i1.1872","url":null,"abstract":"Este artigo apresenta um estudo preliminar sobre as relações entre atividades docentes, a raça dos docentes e o Índice Geral de Cursos (IGC), o principal indicador de qualidade do ensino superior. Para isso, três modelos de regressão linear múltipla foram estimados, acompanhados de uma análise descritiva. Os resultados indicam a importância da participação em pesquisa e da bolsa de pesquisa para o aumento do indicador. Políticas de apoio a atividades docentes além do ensino podem resultar em maior capacitação de professores e alunos. Do ponto de vista de equidade, o aumento da proporção de docentes brancos melhora o IGC, enquanto o aumento de docentes pardos gera uma piora no índice. Isso aponta para a necessidade de estudos mais profundos sobre a equidade docente no ensino superior.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75828577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-25DOI: 10.29215/pecen.v6i0.1900
J. L. Ferreira, N. Rodrigues, Clarice Maria Araújo Silva, Jacilene Sousa Uchôa, Fábio Pereira dos Santos, E. B. Andrade
O mustelídeo Galictis cuja possui uma vasta distribuição na América do Sul, porém aindaexistem algumas lacunas quanto a sua distribuição geográfica, principalmente no nordeste brasileiro.Desse modo, este trabalho apresenta o primeiro registro documentado de G. cuja no estado do Piauí efornece um mapa atualizado da distribuição geográfica da espécie na região Nordeste do Brasil. Umafêmea adulta foi encontrada acidentalmente no município de Lagoa de São Francisco, norte do Piauí,nordeste do Brasil. Assim, acrescentamos informação importante acerca da ampliação da distribuiçãogeográfica da espécie, na expectativa de contribuir para o conhecimento da biologia e da conservaçãodesse mustelídeo.
Galictis鼩鼱在南美洲分布广泛，但其地理分布仍有一些差距，特别是在巴西东北部。因此，本研究首次在piaui州记录了G. cuja的记录，并提供了该物种在巴西东北部的最新地理分布地图。在巴西东北部piaui北部的Lagoa de sao Francisco市偶然发现了一只成年雌性。因此，我们增加了关于扩大该物种地理分布的重要信息，希望对该物种的生物学知识和保护做出贡献。
{"title":"Primeiro registro documentado do furão-pequeno Galictis cuja (Molina, 1782) no estado do Piauí, Nordeste do Brasil","authors":"J. L. Ferreira, N. Rodrigues, Clarice Maria Araújo Silva, Jacilene Sousa Uchôa, Fábio Pereira dos Santos, E. B. Andrade","doi":"10.29215/pecen.v6i0.1900","DOIUrl":"https://doi.org/10.29215/pecen.v6i0.1900","url":null,"abstract":"O mustelídeo Galictis cuja possui uma vasta distribuição na América do Sul, porém aindaexistem algumas lacunas quanto a sua distribuição geográfica, principalmente no nordeste brasileiro.Desse modo, este trabalho apresenta o primeiro registro documentado de G. cuja no estado do Piauí efornece um mapa atualizado da distribuição geográfica da espécie na região Nordeste do Brasil. Umafêmea adulta foi encontrada acidentalmente no município de Lagoa de São Francisco, norte do Piauí,nordeste do Brasil. Assim, acrescentamos informação importante acerca da ampliação da distribuiçãogeográfica da espécie, na expectativa de contribuir para o conhecimento da biologia e da conservaçãodesse mustelídeo.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":"284 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76842239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-06DOI: 10.5433/1679-0375.2022v43n1p75
G. Moro, Rodrigo dos Santos Veloso Martins, T. Giglio
The use of machine learning techniques in thermoenergetic performance studies of buildings emerges as an alternative to conventional methods which analysis require greater data complexity. This research aims to apply a machine learning technique in the study of energy efficiency of a building executed in a light construction system. Thus, an algorithm was implemented referring to an optimized model of classification and regression tree (CART) for application in a data set. This data set includes 2048 parametric simulations of a housing in a light construction system to the climate of the city of São Paulo, whose output indicators are the annual thermal load for heating and the annual thermal load for cooling. From the application of a tree pruning methodology and the use of Grid Search and k-fold Cross Validation techniques, the training and testing of the model was repeated 100 times, thus obtaining average results of 1.11% of error for heating loads and 1.52% of error for predicting cooling loads. Subsequently, a sensitivity analysis was performed, revealing the thermal transmittance property of the walls as the parameter with the greatest influence on the prediction of heating load and the condition of contact between the ground and the floor as the parameter with the greatest influence on the prediction of cooling load. Finally, decision trees were generated for visual analysis of strategies that can be adopted to obtain better levels of thermoenergetic performance. Thus, a more simplified diagnosis of energy efficiency was obtained, with low complexity in the interpretation of its results, favoring greater diffusion of the technology in light systems.
{"title":"Aplicação de um modelo de aprendizado de máquina em estudo de eficiência energética de edificações: foco para sistemas construtivos leves","authors":"G. Moro, Rodrigo dos Santos Veloso Martins, T. Giglio","doi":"10.5433/1679-0375.2022v43n1p75","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1p75","url":null,"abstract":"The use of machine learning techniques in thermoenergetic performance studies of buildings emerges as an alternative to conventional methods which analysis require greater data complexity. This research aims to apply a machine learning technique in the study of energy efficiency of a building executed in a light construction system. Thus, an algorithm was implemented referring to an optimized model of classification and regression tree (CART) for application in a data set. This data set includes 2048 parametric simulations of a housing in a light construction system to the climate of the city of São Paulo, whose output indicators are the annual thermal load for heating and the annual thermal load for cooling. From the application of a tree pruning methodology and the use of Grid Search and k-fold Cross Validation techniques, the training and testing of the model was repeated 100 times, thus obtaining average results of 1.11% of error for heating loads and 1.52% of error for predicting cooling loads. Subsequently, a sensitivity analysis was performed, revealing the thermal transmittance property of the walls as the parameter with the greatest influence on the prediction of heating load and the condition of contact between the ground and the floor as the parameter with the greatest influence on the prediction of cooling load. Finally, decision trees were generated for visual analysis of strategies that can be adopted to obtain better levels of thermoenergetic performance. Thus, a more simplified diagnosis of energy efficiency was obtained, with low complexity in the interpretation of its results, favoring greater diffusion of the technology in light systems.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43031869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.5433/1679-0375.2022v43n1p63
W. Mazer, Wilhen Carmelo Salles Kuchta, Matheus David Inocente Domingos
The main purpose of this paper was to analyze the most important properties of concrete paving blocks (CBP’s) prepared with crushed polyethylene terephthalate (PET) particles derived from soda bottles, by considering PET contents equal to 15, 25 and 35% by volume. Standardized water absorption and compressive strength tests after 21 and 28 curing days were selected. By replacing 15% of conventional aggregates by PET, a maximum increase of 25% in the characteristic compressive strength (fpk) becomes visible and the average value of 32.12 MPa is close to the minimum required value for standard traffic (35 MPa). This may be attributed to the higher interlocking level of the plastic particles within the fractured surfaces of the concrete matrix, as well as the proper amounts of plastics, natural aggregates and Portland cement in the sample and the high elastic modulus of PET. However, the fpk values decreased up to 26% and 66% for plastic contents equal to 25 and 35% by volume, respectively. Despite the general recommendation of not using the CBP’s in pavement surfaces due to the insufficient compressive strength, they may be applied on non-traffic areas such as landscapes, walkways and pedestrian plazas.
{"title":"Mechanical properties of interlocking concrete paving blocks prepared with waste PET bottles","authors":"W. Mazer, Wilhen Carmelo Salles Kuchta, Matheus David Inocente Domingos","doi":"10.5433/1679-0375.2022v43n1p63","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1p63","url":null,"abstract":"The main purpose of this paper was to analyze the most important properties of concrete paving blocks (CBP’s) prepared with crushed polyethylene terephthalate (PET) particles derived from soda bottles, by considering PET contents equal to 15, 25 and 35% by volume. Standardized water absorption and compressive strength tests after 21 and 28 curing days were selected. By replacing 15% of conventional aggregates by PET, a maximum increase of 25% in the characteristic compressive strength (fpk) becomes visible and the average value of 32.12 MPa is close to the minimum required value for standard traffic (35 MPa). This may be attributed to the higher interlocking level of the plastic particles within the fractured surfaces of the concrete matrix, as well as the proper amounts of plastics, natural aggregates and Portland cement in the sample and the high elastic modulus of PET. However, the fpk values decreased up to 26% and 66% for plastic contents equal to 25 and 35% by volume, respectively. Despite the general recommendation of not using the CBP’s in pavement surfaces due to the insufficient compressive strength, they may be applied on non-traffic areas such as landscapes, walkways and pedestrian plazas.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46946916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.5433/1679-0375.2022v43n1p31
Luiz Fellipe Nogueirão, Márcio Turra de Ávila, A. Moraes, Luben Cabezas Gómez, D. Módolo, Devesh Shrestha
Brazil has been among the countries with the cleanest energy matrix in the world. The country showed high growth rates on the economy during the first years of the 21st, which brought to a rapid demand on energy supply. The situation got worser with long dry seasons, resulting on the commissioning of several thermoelectric plants. In the sugar-alcohol sector, the cogeneration became essential. In this context, the use of biomass for the generation and burning of biogas shows great potential in the production of electricity and heat. The discussed study involves the design of a biogas cogeneration system for the Federal University of São Carlos. The considered biomass originates from the campus itself and is composed of organic waste. The system consists of a modified diesel engine, accoupled to an electric generator and three heat exchangers. The monthly production of electricity is 7,7 MWh with a power of 30 kW. The monthly production of thermal energy is 9,8 MWh with a power of 37,6 kW. The costs are quoted adding up to R$ 162,877.00 for the complete system. The annual savings with the system is estimated at R$ 91,126.40, reaching an amortization time of one year and ten months.
{"title":"Project of a cogeneration system using biogas","authors":"Luiz Fellipe Nogueirão, Márcio Turra de Ávila, A. Moraes, Luben Cabezas Gómez, D. Módolo, Devesh Shrestha","doi":"10.5433/1679-0375.2022v43n1p31","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1p31","url":null,"abstract":"Brazil has been among the countries with the cleanest energy matrix in the world. The country showed high growth rates on the economy during the first years of the 21st, which brought to a rapid demand on energy supply. The situation got worser with long dry seasons, resulting on the commissioning of several thermoelectric plants. In the sugar-alcohol sector, the cogeneration became essential. In this context, the use of biomass for the generation and burning of biogas shows great potential in the production of electricity and heat. The discussed study involves the design of a biogas cogeneration system for the Federal University of São Carlos. The considered biomass originates from the campus itself and is composed of organic waste. The system consists of a modified diesel engine, accoupled to an electric generator and three heat exchangers. The monthly production of electricity is 7,7 MWh with a power of 30 kW. The monthly production of thermal energy is 9,8 MWh with a power of 37,6 kW. The costs are quoted adding up to R$ 162,877.00 for the complete system. The annual savings with the system is estimated at R$ 91,126.40, reaching an amortization time of one year and ten months.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43017823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.5433/1679-0375.2022v43n1p55
Peter Cristian Lother, Romano Timofeiczyk Junior, V. Hoeflich, S. Weber
This article aims to investigate the process of implementation of Lean Manufacturing (LM) in companies in the North Furniture Center of Santa Catarina, seeking to identify its adherence to the concepts of strategic planning to ensure its success, within a log-term perspective. This article is based on a qualitative search with this furniture center to identify elements, through data analysis that allowed understanding the dynamics that were applied in this process of LM implementation and its interface with the strategic operations planning. Thus, as a result of this research, the study presented the main characteristics and behaviors related to the concepts of strategic planning aligned with this LM implementation process, which were found: staff training, communication, support for problem solving, monitoring of indicators, review and regular improvements. The study provided important guidance on the best practices for a consistent process for implementing the LM in order to obtain more robust and sustainable results for companies through the commitment of employees
{"title":"Lean manufacturing in the north furniture polo of Santa Catarina from the perspective of strategic planning","authors":"Peter Cristian Lother, Romano Timofeiczyk Junior, V. Hoeflich, S. Weber","doi":"10.5433/1679-0375.2022v43n1p55","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1p55","url":null,"abstract":"This article aims to investigate the process of implementation of Lean Manufacturing (LM) in companies in the North Furniture Center of Santa Catarina, seeking to identify its adherence to the concepts of strategic planning to ensure its success, within a log-term perspective. This article is based on a qualitative search with this furniture center to identify elements, through data analysis that allowed understanding the dynamics that were applied in this process of LM implementation and its interface with the strategic operations planning. Thus, as a result of this research, the study presented the main characteristics and behaviors related to the concepts of strategic planning aligned with this LM implementation process, which were found: staff training, communication, support for problem solving, monitoring of indicators, review and regular improvements. The study provided important guidance on the best practices for a consistent process for implementing the LM in order to obtain more robust and sustainable results for companies through the commitment of employees","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44619982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-01DOI: 10.5433/1679-0375.2022v43n1p45
Marcelo Henrique Jeronymo, T. Abrão
This work deals with power and spectrum allocation approaches for massive MIMO (M-MIMO) systems. An analysis is made to verify the efficiency of the solutions provided by schemes used for the spectral and energy efficiency (SE-EE) trade-off problem in massive antenna-based wireless communication systems. We first introduce the Geometry Based Stochastic Model (GBSM) channel model (One-ring model), describing the behavior of a uniform linear array of antennas (ULA) arrangement, revealing how the channel parameters affect the channel capacity. We also show that under this model, the SE still increases without boundary when the massive number of base-station (BS) antennas $M$ increases, provided that pilot contamination is substantially mitigated or eliminated but when the number of users equipment (UEs) $K$ increases with a fixed number of antennas in the BS, there is a increasing limitation from the combiners in mitigating the inter-user interference, making decoding difficult. The downlink (DL) M-MIMO scenario is analyzed, by introducing the generalized power allocation problem and derived the max-min fairness scheme from it. We propose a procedure to solve the max-min problem and
{"title":"Max-Min fairness-based resource allocation in massive MIMO systems","authors":"Marcelo Henrique Jeronymo, T. Abrão","doi":"10.5433/1679-0375.2022v43n1p45","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1p45","url":null,"abstract":"This work deals with power and spectrum allocation approaches for massive MIMO (M-MIMO) systems. An analysis is made to verify the efficiency of the solutions provided by schemes used for the spectral and energy efficiency (SE-EE) trade-off problem in massive antenna-based wireless communication systems. We first introduce the Geometry Based Stochastic Model (GBSM) channel model (One-ring model), describing the behavior of a uniform linear array of antennas (ULA) arrangement, revealing how the channel parameters affect the channel capacity. We also show that under this model, the SE still increases without boundary when the massive number of base-station (BS) antennas $M$ increases, provided that pilot contamination is substantially mitigated or eliminated but when the number of users equipment (UEs) $K$ increases with a fixed number of antennas in the BS, there is a increasing limitation from the combiners in mitigating the inter-user interference, making decoding difficult. The downlink (DL) M-MIMO scenario is analyzed, by introducing the generalized power allocation problem and derived the max-min fairness scheme from it. We propose a procedure to solve the max-min problem and ","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47421428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-17DOI: 10.5433/1679-0375.2022v43n1espp3
A. Castelo, G. Tavares, Juliana Bertoco
In this paper we introduce a technique to deal with implicit differential equations exhibiting singularities. Our approach is a geometrical one, we use the concept of contact structure on a manifold associated with the differential equation. In this setting we prove an existence and uniqueness theorem. We also show how it relates to known geometric results for this kind of equation. We also indicate how the method can be implemented by using continuation methods techniques and the BDF (Backward Differentiation Formula).
{"title":"Numerical solutions for implicit differential equations with singularities","authors":"A. Castelo, G. Tavares, Juliana Bertoco","doi":"10.5433/1679-0375.2022v43n1espp3","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1espp3","url":null,"abstract":"In this paper we introduce a technique to deal with implicit differential equations exhibiting singularities. Our approach is a geometrical one, we use the concept of contact structure on a manifold associated with the differential equation. In this setting we prove an existence and uniqueness theorem. We also show how it relates to known geometric results for this kind of equation. We also indicate how the method can be implemented by using continuation methods techniques and the BDF (Backward Differentiation Formula).","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48114636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-05-17DOI: 10.5433/1679-0375.2022v43n1espp17
J. S. Azevedo, Lucas Farias Palma
A seismic traveltime inversion method is proposed for building smooth velocity models using traveltime observed on irregular surface. Model parameterization in this study is described by a piecewise constant velocity field on a rectangular grid parameterized by sigmodal functions, which is beneficial for the description of irregular surface with high degree of approximation. The velocity field is defined in the rectangular grid which is used for the description of velocity distribution everywhere in the model sigmoidal interpolation. In addition, we use the simple Genetic Algorithm for the inversion procedure. Through this global scope inversion method, we provide high-resolution estimates of the model parameter and ensure that the results obtained are in accordance with the actual data. Our method is validated with synthetic examples of heterogeneous isotropic media and compared to Simulating Annealing. The inverted velocity models and approximate ray paths obtained coincide well with the trajectories simulated using the seismic ray tracing in synthetic heterogeneous isotropic media.
{"title":"Inversion of velocity models using genetic algorithm method with sigmoidal parameterization","authors":"J. S. Azevedo, Lucas Farias Palma","doi":"10.5433/1679-0375.2022v43n1espp17","DOIUrl":"https://doi.org/10.5433/1679-0375.2022v43n1espp17","url":null,"abstract":"A seismic traveltime inversion method is proposed for building smooth velocity models using traveltime observed on irregular surface. Model parameterization in this study is described by a piecewise constant velocity field on a rectangular grid parameterized by sigmodal functions, which is beneficial for the description of irregular surface with high degree of approximation. The velocity field is defined in the rectangular grid which is used for the description of velocity distribution everywhere in the model sigmoidal interpolation. In addition, we use the simple Genetic Algorithm for the inversion procedure. Through this global scope inversion method, we provide high-resolution estimates of the model parameter and ensure that the results obtained are in accordance with the actual data. Our method is validated with synthetic examples of heterogeneous isotropic media and compared to Simulating Annealing. The inverted velocity models and approximate ray paths obtained coincide well with the trajectories simulated using the seismic ray tracing in synthetic heterogeneous isotropic media.","PeriodicalId":30173,"journal":{"name":"Semina Ciencias Exatas e Tecnologicas","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46659990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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