O mercado de trabalho dos motoristas de caminhão no Brasil: caracterização e avaliação do efeito ... more O mercado de trabalho dos motoristas de caminhão no Brasil: caracterização e avaliação do efeito de leis trabalhistas / Lucas Lima.-versão revisada de acordo com a resolução CoPGr 6018 de 2011.-Piracicaba, 2018. 100 p. Dissertação (Mestrado)-USP / Escola Superior de Agricultura "Luiz de Queiroz". 1. Mercado de trabalho 2. Motoristas de caminhão 3. Jornada de trabalho 4. Diferenças em diferenças. I. Título.
2020 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM)
Despite the valuable social interactions that online media promote, these systems provide space f... more Despite the valuable social interactions that online media promote, these systems provide space for speech that would be potentially detrimental to different groups of people. The moderation of content imposed by many social media has motivated the emergence of a new social system for free speech named Gab, which lacks moderation of content. This article characterizes and compares moderated textual data from Twitter with a set of unmoderated data from Gab. In particular, we analyze distinguishing characteristics of moderated and unmoderated content in terms of linguistic features, evaluate hate speech and its different forms in both environments. Our work shows that unmoderated content presents different psycholinguistic features, more negative sentiment and higher toxicity. Our findings support that unmoderated environments may have proportionally more online hate speech. We hope our analysis and findings contribute to the debate about hate speech and benefit systems aiming at deploying hate speech detection approaches.
2019 IEEE 32nd International Symposium on Computer-Based Medical Systems (CBMS)
Lung cancer is the leading cause of cancer mortality, accounting for approximately 20% of all can... more Lung cancer is the leading cause of cancer mortality, accounting for approximately 20% of all cancer-related deaths. Patients diagnosed in the early stages have a 1-year survival rate of 81-85% while in an advanced stage have 15-19% chances of survival. Therefore, it is very necessary to diagnose lung cancer in early stages in malignant or benign, when the nodules are still very small, but it is a complex task even for experienced specialists and presents some challenges. To assist specialists, computer-aided diagnosis systems have been used to improve the accuracy in the diagnosis. In this paper, we exploit the use of a technique of hyperparameter tuning to find the best architecture of a Convolutional Neural Network to classify small pulmonary nodules balanced with diameter 5-10mm. The best results achieved were an error rate of 12%, sensitivity of 94%, specificity of 83%, accuracy of 88% and F-measure of 89%
Contact resistances are inherent to any device connected to the outside world. Lowering their con... more Contact resistances are inherent to any device connected to the outside world. Lowering their contribution is essential for high-performance applications. This is the case for advanced Si CMOS technologies, for which series resistance parasitics become the main performance detractor from the 14 nm node onwards [1-2]. For p-type fin and gate-all-around field effect transistors, focus is placed on Ti contacts to p-Si1-xGex source/drain (S/D) [3]. Several non-equilibrium doping techniques have been explored to enhance active doping in S/D regions and decrease contact resistivities (ρc) down to ≤ 1x10-9 Ω.cm2. In most cases, low temperature doping processes are used to favor the incorporation of dopants and their activation [4]. Alternative dopants, with higher solid solubilities and advantageous segregation behaviors favoring the formation of dopant-enriched films at the metal-semiconductor interface, are also evaluated. Very low ρc values have e.g. been reported by combining Ga ion im...
Proceedings of the 2nd International Conference on Model-Driven Engineering and Software Development, 2014
We propose a semantics for Sequence Diagrams based on the COMPASS Modelling Language (CML): a for... more We propose a semantics for Sequence Diagrams based on the COMPASS Modelling Language (CML): a formal specification language to model systems of systems. A distinguishing feature of our semantics is that it is defined as part of a larger effort to define the semantics of several diagrams of SysML, a UML profile for systems engineering. We have defined a fairly comprehensive semantics for Sequence Diagrams, which comprises sequential and parallel constructors, loops, breaks, alternatives, synchronous and asynchronous messages. We illustrate our semantics with a scenario of a case study of a system of systems. We also discuss an analysis strategy which involves an integrated view of several diagrams.
Component Based Software Development (CBSD) is an established paradigm to build systems from reus... more Component Based Software Development (CBSD) is an established paradigm to build systems from reusable and loosely coupled units. However, it is still a challenge to ensure, in a scalable way, that desired properties hold for component integration. We present a component based model for UML, including a metamodel, well-formedness conditions and a formal semantics via translation into BRIC. We use (our previous work on) BRIC as an underlying (and totally hidden) component development framework so that our approach benefits from all the formal infrastructure developed for BRIC using CSP (Communicating Sequential Processes). Component composition, specified via UML structural diagrams, ensures, by construction, adherence to classical concurrent properties: our focus is on the preservation of deadlock freedom. Partial automated support is developed as a plug-in to the Astah modelling tool. We illustrate our overall approach with two case studies.
In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liq... more In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liquid desiccant system in an industrial gelatin conveyor dryer. The working fluid is a binary solution of lithium chloride (LiCl) in water. Dry air is used in order to decrease the amount of liquid in the gelatin. Therefore, the environmental air must have its absolute humidity reduced from about 12 g/kg to the project target, which is 5 g/kg. The process is a cycle using an absorption desiccant unit (LiCl in water), where the weak solution absorbs water vapor from the air. In the regenerator, condensation of the solution (desorption) from the moist air occurs. As a result, the steam consumption of the desorber and electrical power used for the vapor compression chiller (with ammonia, NH3, as working fluid) are the primary sources of cost for the factory. To improve the plant’s energy and exergy behaviors, the process is evaluated using a mathematical model of the system processes. In addi...
2018 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), 2018
The moderation of content in many social media systems, such as Twitter and Facebook, motivated t... more The moderation of content in many social media systems, such as Twitter and Facebook, motivated the emergence of a new social network system that promotes free speech, named Gab. Soon after that, Gab has been removed from Google Play Store for violating the company's hate speech policy and it has been rejected by Apple for similar reasons. In this paper we characterize Gab, aiming at understanding who are the users who joined it and what kind of content they share in this system. Our findings show that Gab is a very politically oriented system that hosts banned users from other social networks, some of them due to possible cases of hate speech and association with extremism. We provide the first measurement of news dissemination inside a right-leaning echo chamber, investigating a social media where readers are rarely exposed to content that cuts across ideological lines, but rather are fed with content that reinforces their current political or social views.
Anais do Brazilian Workshop on Social Network Analysis and Mining (BraSNAM), 2015
Estudos apontam que a popularidade de um usuário no Twitter está muito vinculada à quantidade de ... more Estudos apontam que a popularidade de um usuário no Twitter está muito vinculada à quantidade de seguidores que o mesmo possui, enquanto um grande número de citações no meio científico e é sinônimo de alto impacto acadêmico. Neste contexto, este estudo criou uma base de dados de pesquisa dores com contas no Twitter e no Google Acadêmico com o objetivo de calcular o índice Gilberto-Arruda. Os resultados encontrados mostram que existem pesquisadores que neste estudo são associados à João Gilberto e outros à Geisy Arruda, isto e é, alguns pesquisadores possuem poucos seguidores porém muitas citações enquanto outros possuem muitos seguidores e poucas citações. Foi desenvolvida uma aplicação web que permite aos pesquisadores consultar qual o seu índice Gilberto-Arruda.
We provide a general framework for investigating partial identification of structural dynamic dis... more We provide a general framework for investigating partial identification of structural dynamic discrete choice models and their counterfactuals, along with uniformly valid inference procedures. In doing so, we derive sharp bounds for the model parameters, counterfactual behavior, and low-dimensional outcomes of interest, such as the average welfare effects of hypothetical policy interventions. We characterize the properties of the sets analytically and show that when the target outcome of interest is a scalar, its identified set is an interval whose endpoints can be calculated by solving well-behaved constrained optimization problems via standard algorithms. We obtain a uniformly valid inference procedure by an appropriate application of subsampling. To illustrate the performance and computational feasibility of the method, we consider both a Monte Carlo study of firm entry/exit, and an empirical model of export decisions applied to plant-level data from Colombian manufacturing industries. In these applications, we demonstrate how the identified sets shrink as we incorporate alternative model restrictions, providing intuition regarding the source and strength of identification.
In this paper we describe three new species of Tetilla from stretches of the coast of Bahia, nort... more In this paper we describe three new species of Tetilla from stretches of the coast of Bahia, northeastern Brazil, all collected in shallow waters and soft bottoms. Tetilla pentatriaena sp. nov. is distinct from other species of the genus by the unique possession of five categories of triaenes: two of protriaenes and three of anatriaenes. Tetilla muricyi sp. nov. and Tetilla rodriguesi sp. nov. are the first species in the genus registered exclusively from mangrove ecosystems and are distinct from most species of Tetilla by their lack of microscleres. Tetilla muricyi sp. nov. differs from all species by its spiculation and by having a reticulate skeleton of secondary oxeas. Tetilla rodriguesi sp. nov. differs from other species without sigmaspires by the presence of three categories of oxeas, two of trichoidal protriaenes and one of exclusively rhizoidal anatriaenes. In addition to the three new species described here we also provided one identification key to the Tetilla species occ...
Journal of Neurological Surgery Part B: Skull Base, 2017
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Anais dos Workshops do V Congresso Brasileiro de Informática na Educação (CBIE 2016), 2016
The Internet of things has features and operation differentiated from traditional networks, being... more The Internet of things has features and operation differentiated from traditional networks, being a potential technology for usage in various areas of the educational context. Based on that technology, this article proposes to build a system computational established among heterogeneous objects to improve the apprentice learning process for Brazilian Sign Language and to promote social inclusion of brazilian deaf. Resumo. A Internet das Coisas possui características e funcionamento diferenciados das redes tradicionais, sendo uma potencial tecnologia para uso em diversas áreas do âmbito educacional. Baseado nessa tecnologia, este artigo propõe a construção de um sistema computacional estabelecido por objetos heterogêneos para aperfeiçoar o processo de ensino-aprendizagem da Língua Brasileira de Sinais e promover a inclusão social dos surdos brasileiros.
During the design of systems, models usually evolve from a conceptual level to a more concrete le... more During the design of systems, models usually evolve from a conceptual level to a more concrete level that is close to how the implementation should be. In a stepwise development, it is required that lower-level models conform to the properties of higher-level models. In this work, we propose a strategy for verifying the refinement of UML sequence diagrams that uses a formal semantics defined in terms of CSP. In order to allow designers to benefit from this strategy we have implemented it in a modelling tool. Such a tool analyses if a sequence diagram is refined by another, that is, we check if the latter preserves the traces of the former sequence diagram. The main contributions of this paper are: (i) the definition of four different notions of sequence diagrams refinement; (ii) an approach to verify the refinement of sequence diagrams in CSP; and (iii) the development of a tool that allows our refinement notions to be verified without any knowledge of the underlying formal semantics. We illustrate our analysis with a text messaging case study.
O mercado de trabalho dos motoristas de caminhão no Brasil: caracterização e avaliação do efeito ... more O mercado de trabalho dos motoristas de caminhão no Brasil: caracterização e avaliação do efeito de leis trabalhistas / Lucas Lima.-versão revisada de acordo com a resolução CoPGr 6018 de 2011.-Piracicaba, 2018. 100 p. Dissertação (Mestrado)-USP / Escola Superior de Agricultura "Luiz de Queiroz". 1. Mercado de trabalho 2. Motoristas de caminhão 3. Jornada de trabalho 4. Diferenças em diferenças. I. Título.
2020 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM)
Despite the valuable social interactions that online media promote, these systems provide space f... more Despite the valuable social interactions that online media promote, these systems provide space for speech that would be potentially detrimental to different groups of people. The moderation of content imposed by many social media has motivated the emergence of a new social system for free speech named Gab, which lacks moderation of content. This article characterizes and compares moderated textual data from Twitter with a set of unmoderated data from Gab. In particular, we analyze distinguishing characteristics of moderated and unmoderated content in terms of linguistic features, evaluate hate speech and its different forms in both environments. Our work shows that unmoderated content presents different psycholinguistic features, more negative sentiment and higher toxicity. Our findings support that unmoderated environments may have proportionally more online hate speech. We hope our analysis and findings contribute to the debate about hate speech and benefit systems aiming at deploying hate speech detection approaches.
2019 IEEE 32nd International Symposium on Computer-Based Medical Systems (CBMS)
Lung cancer is the leading cause of cancer mortality, accounting for approximately 20% of all can... more Lung cancer is the leading cause of cancer mortality, accounting for approximately 20% of all cancer-related deaths. Patients diagnosed in the early stages have a 1-year survival rate of 81-85% while in an advanced stage have 15-19% chances of survival. Therefore, it is very necessary to diagnose lung cancer in early stages in malignant or benign, when the nodules are still very small, but it is a complex task even for experienced specialists and presents some challenges. To assist specialists, computer-aided diagnosis systems have been used to improve the accuracy in the diagnosis. In this paper, we exploit the use of a technique of hyperparameter tuning to find the best architecture of a Convolutional Neural Network to classify small pulmonary nodules balanced with diameter 5-10mm. The best results achieved were an error rate of 12%, sensitivity of 94%, specificity of 83%, accuracy of 88% and F-measure of 89%
Contact resistances are inherent to any device connected to the outside world. Lowering their con... more Contact resistances are inherent to any device connected to the outside world. Lowering their contribution is essential for high-performance applications. This is the case for advanced Si CMOS technologies, for which series resistance parasitics become the main performance detractor from the 14 nm node onwards [1-2]. For p-type fin and gate-all-around field effect transistors, focus is placed on Ti contacts to p-Si1-xGex source/drain (S/D) [3]. Several non-equilibrium doping techniques have been explored to enhance active doping in S/D regions and decrease contact resistivities (ρc) down to ≤ 1x10-9 Ω.cm2. In most cases, low temperature doping processes are used to favor the incorporation of dopants and their activation [4]. Alternative dopants, with higher solid solubilities and advantageous segregation behaviors favoring the formation of dopant-enriched films at the metal-semiconductor interface, are also evaluated. Very low ρc values have e.g. been reported by combining Ga ion im...
Proceedings of the 2nd International Conference on Model-Driven Engineering and Software Development, 2014
We propose a semantics for Sequence Diagrams based on the COMPASS Modelling Language (CML): a for... more We propose a semantics for Sequence Diagrams based on the COMPASS Modelling Language (CML): a formal specification language to model systems of systems. A distinguishing feature of our semantics is that it is defined as part of a larger effort to define the semantics of several diagrams of SysML, a UML profile for systems engineering. We have defined a fairly comprehensive semantics for Sequence Diagrams, which comprises sequential and parallel constructors, loops, breaks, alternatives, synchronous and asynchronous messages. We illustrate our semantics with a scenario of a case study of a system of systems. We also discuss an analysis strategy which involves an integrated view of several diagrams.
Component Based Software Development (CBSD) is an established paradigm to build systems from reus... more Component Based Software Development (CBSD) is an established paradigm to build systems from reusable and loosely coupled units. However, it is still a challenge to ensure, in a scalable way, that desired properties hold for component integration. We present a component based model for UML, including a metamodel, well-formedness conditions and a formal semantics via translation into BRIC. We use (our previous work on) BRIC as an underlying (and totally hidden) component development framework so that our approach benefits from all the formal infrastructure developed for BRIC using CSP (Communicating Sequential Processes). Component composition, specified via UML structural diagrams, ensures, by construction, adherence to classical concurrent properties: our focus is on the preservation of deadlock freedom. Partial automated support is developed as a plug-in to the Astah modelling tool. We illustrate our overall approach with two case studies.
In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liq... more In this paper, an energy and exergy analysis is applied to the air dehumidification unit of a liquid desiccant system in an industrial gelatin conveyor dryer. The working fluid is a binary solution of lithium chloride (LiCl) in water. Dry air is used in order to decrease the amount of liquid in the gelatin. Therefore, the environmental air must have its absolute humidity reduced from about 12 g/kg to the project target, which is 5 g/kg. The process is a cycle using an absorption desiccant unit (LiCl in water), where the weak solution absorbs water vapor from the air. In the regenerator, condensation of the solution (desorption) from the moist air occurs. As a result, the steam consumption of the desorber and electrical power used for the vapor compression chiller (with ammonia, NH3, as working fluid) are the primary sources of cost for the factory. To improve the plant’s energy and exergy behaviors, the process is evaluated using a mathematical model of the system processes. In addi...
2018 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), 2018
The moderation of content in many social media systems, such as Twitter and Facebook, motivated t... more The moderation of content in many social media systems, such as Twitter and Facebook, motivated the emergence of a new social network system that promotes free speech, named Gab. Soon after that, Gab has been removed from Google Play Store for violating the company's hate speech policy and it has been rejected by Apple for similar reasons. In this paper we characterize Gab, aiming at understanding who are the users who joined it and what kind of content they share in this system. Our findings show that Gab is a very politically oriented system that hosts banned users from other social networks, some of them due to possible cases of hate speech and association with extremism. We provide the first measurement of news dissemination inside a right-leaning echo chamber, investigating a social media where readers are rarely exposed to content that cuts across ideological lines, but rather are fed with content that reinforces their current political or social views.
Anais do Brazilian Workshop on Social Network Analysis and Mining (BraSNAM), 2015
Estudos apontam que a popularidade de um usuário no Twitter está muito vinculada à quantidade de ... more Estudos apontam que a popularidade de um usuário no Twitter está muito vinculada à quantidade de seguidores que o mesmo possui, enquanto um grande número de citações no meio científico e é sinônimo de alto impacto acadêmico. Neste contexto, este estudo criou uma base de dados de pesquisa dores com contas no Twitter e no Google Acadêmico com o objetivo de calcular o índice Gilberto-Arruda. Os resultados encontrados mostram que existem pesquisadores que neste estudo são associados à João Gilberto e outros à Geisy Arruda, isto e é, alguns pesquisadores possuem poucos seguidores porém muitas citações enquanto outros possuem muitos seguidores e poucas citações. Foi desenvolvida uma aplicação web que permite aos pesquisadores consultar qual o seu índice Gilberto-Arruda.
We provide a general framework for investigating partial identification of structural dynamic dis... more We provide a general framework for investigating partial identification of structural dynamic discrete choice models and their counterfactuals, along with uniformly valid inference procedures. In doing so, we derive sharp bounds for the model parameters, counterfactual behavior, and low-dimensional outcomes of interest, such as the average welfare effects of hypothetical policy interventions. We characterize the properties of the sets analytically and show that when the target outcome of interest is a scalar, its identified set is an interval whose endpoints can be calculated by solving well-behaved constrained optimization problems via standard algorithms. We obtain a uniformly valid inference procedure by an appropriate application of subsampling. To illustrate the performance and computational feasibility of the method, we consider both a Monte Carlo study of firm entry/exit, and an empirical model of export decisions applied to plant-level data from Colombian manufacturing industries. In these applications, we demonstrate how the identified sets shrink as we incorporate alternative model restrictions, providing intuition regarding the source and strength of identification.
In this paper we describe three new species of Tetilla from stretches of the coast of Bahia, nort... more In this paper we describe three new species of Tetilla from stretches of the coast of Bahia, northeastern Brazil, all collected in shallow waters and soft bottoms. Tetilla pentatriaena sp. nov. is distinct from other species of the genus by the unique possession of five categories of triaenes: two of protriaenes and three of anatriaenes. Tetilla muricyi sp. nov. and Tetilla rodriguesi sp. nov. are the first species in the genus registered exclusively from mangrove ecosystems and are distinct from most species of Tetilla by their lack of microscleres. Tetilla muricyi sp. nov. differs from all species by its spiculation and by having a reticulate skeleton of secondary oxeas. Tetilla rodriguesi sp. nov. differs from other species without sigmaspires by the presence of three categories of oxeas, two of trichoidal protriaenes and one of exclusively rhizoidal anatriaenes. In addition to the three new species described here we also provided one identification key to the Tetilla species occ...
Journal of Neurological Surgery Part B: Skull Base, 2017
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Anais dos Workshops do V Congresso Brasileiro de Informática na Educação (CBIE 2016), 2016
The Internet of things has features and operation differentiated from traditional networks, being... more The Internet of things has features and operation differentiated from traditional networks, being a potential technology for usage in various areas of the educational context. Based on that technology, this article proposes to build a system computational established among heterogeneous objects to improve the apprentice learning process for Brazilian Sign Language and to promote social inclusion of brazilian deaf. Resumo. A Internet das Coisas possui características e funcionamento diferenciados das redes tradicionais, sendo uma potencial tecnologia para uso em diversas áreas do âmbito educacional. Baseado nessa tecnologia, este artigo propõe a construção de um sistema computacional estabelecido por objetos heterogêneos para aperfeiçoar o processo de ensino-aprendizagem da Língua Brasileira de Sinais e promover a inclusão social dos surdos brasileiros.
During the design of systems, models usually evolve from a conceptual level to a more concrete le... more During the design of systems, models usually evolve from a conceptual level to a more concrete level that is close to how the implementation should be. In a stepwise development, it is required that lower-level models conform to the properties of higher-level models. In this work, we propose a strategy for verifying the refinement of UML sequence diagrams that uses a formal semantics defined in terms of CSP. In order to allow designers to benefit from this strategy we have implemented it in a modelling tool. Such a tool analyses if a sequence diagram is refined by another, that is, we check if the latter preserves the traces of the former sequence diagram. The main contributions of this paper are: (i) the definition of four different notions of sequence diagrams refinement; (ii) an approach to verify the refinement of sequence diagrams in CSP; and (iii) the development of a tool that allows our refinement notions to be verified without any knowledge of the underlying formal semantics. We illustrate our analysis with a text messaging case study.
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Papers by Lucas A P Lima