Cicero Gomes - Academia.edu (original) (raw)

Papers by Cicero Gomes

Research paper thumbnail of Superior Mesenteric Artery Syndrome – An Uncommon Complication After Surgical Corrections of Spinal Deformities

Vascular compression of the third part of the duodenum by the superior mesenteric artery results ... more Vascular compression of the third part of the duodenum by the superior mesenteric artery results in an unusual occlusion of the duodenal transit known as superior mesenteric artery syndrome. This syndrome can occur after surgeries to correct spinal deformities in a rate ranging from 0.5% to 4.7%. It results from a positional alteration of the artery emergency point due to a change in trunk length after surgery. It is associated with risk factors such as low body mass index and weight loss. Patients usually present with intestinal occlusion, abdominal pain, nausea, bilious vomiting, and early satiety. Superior mesenteric artery syndrome must be recognized early to institute an adequate treatment, which can be clinical (with gastric tube for decompression and nutritional support) or require a surgical procedure. Secondary complications related to superior mesenteric artery syndrome include delayed surgical and nutritional recovery, healing problems, and prolonged hospitalization. The ...

Research paper thumbnail of Underwater Vehicle Dynamic Modeling

This paper presents an approach to develop dynamic models of underwater vehicles which have open ... more This paper presents an approach to develop dynamic models of underwater vehicles which have open frame architecture and symmetrical planes. A ROV (Remotely Operated Vehicle) was especially constructed to perform experimental results to validate the used dynamic model approach. This dynamic model validation was performed through confrontation between open loop experiments and simulation results. One of the motivations to develop this research is that the underwater robotics in Brazil is a recent scientific domain, mainly in experimental aspects. It was verified that it is very difficult to obtain two identical open loop responses in two experiments made under the same conditions. This happens because it is difficult to reproduce the initial state of the ROV and the water conditions. Comparisons between experimental and simulation results in open loop showed that the dynamic model reproduce relatively well the experiments, indicating that the model approach can be used to ROVs or AUVs(Autonomous Underwater Vehicles) avec symmetrical planes and open frame architecture.

Research paper thumbnail of Neural Network for Lightning Forecasting in Southeastern Brazil

Ciencia Natura, Sep 1, 2014

This paper introduces a lightning forecasting system using Neural Networks (NN) based on correlat... more This paper introduces a lightning forecasting system using Neural Networks (NN) based on correlations between cloud-to-ground (CG) lightning flash data and meteorological variables obtained from MM5 (Fifth-Generation Penn State/NCAR Mesoscale Model) simulations in southeastern Brazil. Besides the area of nineteen high density lightning subregions selected from non-severe thunderstorms cases, the following model parameters were also used as inputs for the NN: divergence at 850 hPa and 200 hPa, temperature advection at 500 hPa, vertical velocity at 500 hPa, and water vapor-mixing ratio at the surface and 850 hPa. The target output of the neural system was the number of CG lightning flashes that would occur one hour in advance. Four cases, not previously trained, of high density lightning subregions were used to test the system efficiency. Although the testing cases were sufficiently different, a case with no occurrence of lightning has also been included in order to not introduce any bias on the analysis. The results of the lightning forecasting were promising, indicating that the NN technique associated with model variables from numerical simulations can be an efficient tool for predicting flash occurrence appropriately.

Research paper thumbnail of Vapor–liquid equilibria for ethyl acetate+methanol and ethyl acetate+ethanol mixtures: Experimental verification and prediction

Chemical Engineering Research and Design, 2014

ABSTRACT This work aims of the determination of a series of vapor–liquid equilibrium (VLE) experi... more ABSTRACT This work aims of the determination of a series of vapor–liquid equilibrium (VLE) experimental data at low pressure (70 kPa) for binary mixtures of ethyl acetate with methanol and ethanol. The Fischer's ebulliometer was used for the measurements of VLE data. A complete series of equilibrium data was obtained such as pressure, temperature and compositions of the liquid and vapor phases (PTxy). The two VLE data sets were submitted to a thermodynamic consistence test, where the deviations were evaluated in all variables, using the UNIQUAC activity coefficient equation. The magnitude of the average deviations was within the experimental uncertainty satisfying the Gibbs–Duhen equation. The data sets were also used to test the prediction of the UNIFAC model in its original and modified editions and the results were also within experimental uncertainties. Then a series of binary systems containing alcohols (methanol and ethanol) and esters (methyl and ethyl acetate) were collected from the literature for testing systematically the capability of the UNIFAC contribution method for this type of mixtures.

Research paper thumbnail of Manipulator Robots Using Partial-Order Planning

Lecture Notes in Computer Science, 1998

Intelligent task planning executed by manipulators robots and mainly its integration with the dev... more Intelligent task planning executed by manipulators robots and mainly its integration with the development of efficient controllers responsible for the execution of these tasks, constitute a non completely well solved problem, for sure needing more researches. In this way, it was created two computational tools: NONLinear Intelligent Planner (NONLIP), and the Simulator with Inter-face for Manipulators (SIM). Good results have

Research paper thumbnail of On the Use of Deflection Sensors to Estimate the Dynamic of a Flexible Beam

Southern Conference on Computational Modeling, 2009

This article is a theoretical and experimental study of the dynamics of a flexible beam coupled t... more This article is a theoretical and experimental study of the dynamics of a flexible beam coupled to harmonic drive actuator. As a main result we present a technique that allows, from the data provided by some deflection sensors installed on the beam, to estimate the position, the deflection and also other quantities related to the dynamics of the system at

Research paper thumbnail of A new robotic drive joint friction compensation mechanism using neural networks

Journal of The Brazilian Society of Mechanical Sciences and Engineering, 2003

ABSTRACT The knowledge of realistic dynamic models to robotic actuators would be of great aid in ... more ABSTRACT The knowledge of realistic dynamic models to robotic actuators would be of great aid in the synthesis of control laws to robot manipulators, mainly in cases of great precision robotic or even for manipulators with flexible links. In this paper we present a training scheme and propose a structure of neural network (NN) to learn the friction torque of a geared motor drive joint robotic actuator. To train the NN was used experimental data obtained by an harmonic-drive actuator, equipped with an encoder to measure the rotor angular position. It was considered the motor torque and the rotor angular velocity as NN input, while the friction torque was the only output, which was used in the proposition of a non-linear friction compensation mechanism. The experimental results attested the efficiency of the NN friction estimation and compensation with the proposed mechanism.

Research paper thumbnail of A hardware DC motor emulator

Much work have been done lately to develop complex motor control systems. However they always rel... more Much work have been done lately to develop complex motor control systems. However they always rely on a physical drive/motor/encoder setup for experimental results. This paper presents a hardware DC motor emulator that can be synthesized to FPGAs. The emulator ...

Research paper thumbnail of Sobre o uso de sensores de deflexão para estimar a dinâmica de uma lâmina flexível

Vetor Revista De Ciencias Exatas E Engenharias, Dec 6, 2010

This article is a theoretical and experimental study of the dynamics of flexible beams coupled to... more This article is a theoretical and experimental study of the dynamics of flexible beams coupled to an actuator of the type harmonic drive. As a main result we present a technique that allows, from the data provided by some deflection sensors installed on the beam, to estimate the position, the deflection and also other quantities related to the dynamics of the system at any other point of the beam. Experimental tests were performed and demonstrate the excellent performance of this technique.

Research paper thumbnail of Superior Mesenteric Artery Syndrome – An Uncommon Complication After Surgical Corrections of Spinal Deformities

Vascular compression of the third part of the duodenum by the superior mesenteric artery results ... more Vascular compression of the third part of the duodenum by the superior mesenteric artery results in an unusual occlusion of the duodenal transit known as superior mesenteric artery syndrome. This syndrome can occur after surgeries to correct spinal deformities in a rate ranging from 0.5% to 4.7%. It results from a positional alteration of the artery emergency point due to a change in trunk length after surgery. It is associated with risk factors such as low body mass index and weight loss. Patients usually present with intestinal occlusion, abdominal pain, nausea, bilious vomiting, and early satiety. Superior mesenteric artery syndrome must be recognized early to institute an adequate treatment, which can be clinical (with gastric tube for decompression and nutritional support) or require a surgical procedure. Secondary complications related to superior mesenteric artery syndrome include delayed surgical and nutritional recovery, healing problems, and prolonged hospitalization. The ...

Research paper thumbnail of Underwater Vehicle Dynamic Modeling

This paper presents an approach to develop dynamic models of underwater vehicles which have open ... more This paper presents an approach to develop dynamic models of underwater vehicles which have open frame architecture and symmetrical planes. A ROV (Remotely Operated Vehicle) was especially constructed to perform experimental results to validate the used dynamic model approach. This dynamic model validation was performed through confrontation between open loop experiments and simulation results. One of the motivations to develop this research is that the underwater robotics in Brazil is a recent scientific domain, mainly in experimental aspects. It was verified that it is very difficult to obtain two identical open loop responses in two experiments made under the same conditions. This happens because it is difficult to reproduce the initial state of the ROV and the water conditions. Comparisons between experimental and simulation results in open loop showed that the dynamic model reproduce relatively well the experiments, indicating that the model approach can be used to ROVs or AUVs(Autonomous Underwater Vehicles) avec symmetrical planes and open frame architecture.

Research paper thumbnail of Neural Network for Lightning Forecasting in Southeastern Brazil

Ciencia Natura, Sep 1, 2014

This paper introduces a lightning forecasting system using Neural Networks (NN) based on correlat... more This paper introduces a lightning forecasting system using Neural Networks (NN) based on correlations between cloud-to-ground (CG) lightning flash data and meteorological variables obtained from MM5 (Fifth-Generation Penn State/NCAR Mesoscale Model) simulations in southeastern Brazil. Besides the area of nineteen high density lightning subregions selected from non-severe thunderstorms cases, the following model parameters were also used as inputs for the NN: divergence at 850 hPa and 200 hPa, temperature advection at 500 hPa, vertical velocity at 500 hPa, and water vapor-mixing ratio at the surface and 850 hPa. The target output of the neural system was the number of CG lightning flashes that would occur one hour in advance. Four cases, not previously trained, of high density lightning subregions were used to test the system efficiency. Although the testing cases were sufficiently different, a case with no occurrence of lightning has also been included in order to not introduce any bias on the analysis. The results of the lightning forecasting were promising, indicating that the NN technique associated with model variables from numerical simulations can be an efficient tool for predicting flash occurrence appropriately.

Research paper thumbnail of Vapor–liquid equilibria for ethyl acetate+methanol and ethyl acetate+ethanol mixtures: Experimental verification and prediction

Chemical Engineering Research and Design, 2014

ABSTRACT This work aims of the determination of a series of vapor–liquid equilibrium (VLE) experi... more ABSTRACT This work aims of the determination of a series of vapor–liquid equilibrium (VLE) experimental data at low pressure (70 kPa) for binary mixtures of ethyl acetate with methanol and ethanol. The Fischer's ebulliometer was used for the measurements of VLE data. A complete series of equilibrium data was obtained such as pressure, temperature and compositions of the liquid and vapor phases (PTxy). The two VLE data sets were submitted to a thermodynamic consistence test, where the deviations were evaluated in all variables, using the UNIQUAC activity coefficient equation. The magnitude of the average deviations was within the experimental uncertainty satisfying the Gibbs–Duhen equation. The data sets were also used to test the prediction of the UNIFAC model in its original and modified editions and the results were also within experimental uncertainties. Then a series of binary systems containing alcohols (methanol and ethanol) and esters (methyl and ethyl acetate) were collected from the literature for testing systematically the capability of the UNIFAC contribution method for this type of mixtures.

Research paper thumbnail of Manipulator Robots Using Partial-Order Planning

Lecture Notes in Computer Science, 1998

Intelligent task planning executed by manipulators robots and mainly its integration with the dev... more Intelligent task planning executed by manipulators robots and mainly its integration with the development of efficient controllers responsible for the execution of these tasks, constitute a non completely well solved problem, for sure needing more researches. In this way, it was created two computational tools: NONLinear Intelligent Planner (NONLIP), and the Simulator with Inter-face for Manipulators (SIM). Good results have

Research paper thumbnail of On the Use of Deflection Sensors to Estimate the Dynamic of a Flexible Beam

Southern Conference on Computational Modeling, 2009

This article is a theoretical and experimental study of the dynamics of a flexible beam coupled t... more This article is a theoretical and experimental study of the dynamics of a flexible beam coupled to harmonic drive actuator. As a main result we present a technique that allows, from the data provided by some deflection sensors installed on the beam, to estimate the position, the deflection and also other quantities related to the dynamics of the system at

Research paper thumbnail of A new robotic drive joint friction compensation mechanism using neural networks

Journal of The Brazilian Society of Mechanical Sciences and Engineering, 2003

ABSTRACT The knowledge of realistic dynamic models to robotic actuators would be of great aid in ... more ABSTRACT The knowledge of realistic dynamic models to robotic actuators would be of great aid in the synthesis of control laws to robot manipulators, mainly in cases of great precision robotic or even for manipulators with flexible links. In this paper we present a training scheme and propose a structure of neural network (NN) to learn the friction torque of a geared motor drive joint robotic actuator. To train the NN was used experimental data obtained by an harmonic-drive actuator, equipped with an encoder to measure the rotor angular position. It was considered the motor torque and the rotor angular velocity as NN input, while the friction torque was the only output, which was used in the proposition of a non-linear friction compensation mechanism. The experimental results attested the efficiency of the NN friction estimation and compensation with the proposed mechanism.

Research paper thumbnail of A hardware DC motor emulator

Much work have been done lately to develop complex motor control systems. However they always rel... more Much work have been done lately to develop complex motor control systems. However they always rely on a physical drive/motor/encoder setup for experimental results. This paper presents a hardware DC motor emulator that can be synthesized to FPGAs. The emulator ...

Research paper thumbnail of Sobre o uso de sensores de deflexão para estimar a dinâmica de uma lâmina flexível

Vetor Revista De Ciencias Exatas E Engenharias, Dec 6, 2010

This article is a theoretical and experimental study of the dynamics of flexible beams coupled to... more This article is a theoretical and experimental study of the dynamics of flexible beams coupled to an actuator of the type harmonic drive. As a main result we present a technique that allows, from the data provided by some deflection sensors installed on the beam, to estimate the position, the deflection and also other quantities related to the dynamics of the system at any other point of the beam. Experimental tests were performed and demonstrate the excellent performance of this technique.