Edgar Junior - Academia.edu (original) (raw)
Papers by Edgar Junior
Revista de Ensino de Engenharia
Este estudo apresenta uma análise do efeito estroboscópico: uma abordagem didática para ensinar o... more Este estudo apresenta uma análise do efeito estroboscópico: uma abordagem didática para ensinar o fenômeno de aliasing causado pela subamostragem para alunos de graduação em Engenharia de Computação. O artigo em si é um resultado concreto da metodologia e procedimentos utilizados para ensinar o assunto supramencionado. Uma análise matemática do efeito estroboscópico é realizada e, então, as frequências existentes nesse fenômeno por meio do giro de um ventilador iluminado por uma lâmpada estroboscópica são relacionadas. Além disso, dada a importância da visão humana neste contexto, os diferentes efeitos percebidos à luz do processo de amostragem são explicados. Para representar o movimento da fita vermelha colada em uma das hélices de um ventilador, um simulador foi desenvolvido, cuja visualização do fenômeno é possível, considerando as variáveis levadas em conta na etapa de modelagem matemática. Um conjunto de testes foi feito em cada intervalo designado, a fim de correlacionar as faixas de frequência obtidas analiticamente com o movimento percebido pelo olho humano, associando ambos e validando a modelagem. Com os resultados deste estudo é possível compreender a influência da frequência no processo de amostragem, bem como suas principais implicações, tais como o fenômeno aliasing: o resultado do processo de subamostragem.
In this work we present a vectorial analysis of the two-ray model, as well as a vectorial analysi... more In this work we present a vectorial analysis of the two-ray model, as well as a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the analysis of the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields) and non-approximated analysis (considering dipole's gain and vectorial analysis) is provided as well as an analysis of the error versus r distance. A comparison between vertical and horizontal components of the electric field is also carried out. Regarding the street model, the street is modeled as a multislit waveguide, and horizontal and vertical polarizations are investigated. As in the tworay model, a comparison between the approximated and non-approximated analysis is provided as well as a comparison between the total field and the field due to lateral reflections only. Still for the street model, slits are inserted and comparisons and analyses are made. Comparisons provided show that a vectorial and gain analysis can be a very useful tool toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004., 2004
ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Eart... more ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Earth, which consists of a ray that arrive at the receptor along a straight line and of a ray that arrive at the receptor after a ground reflection. This model is analyzed throughout two manners for parallel polarization: with and without approximations regarding to the summation of the electric fields at the point of reception. For the model analyzed without approximations, an ideal dipole is assumed as a transmitting aerial and a vectorial analysis is accounted. For the model analyzed with approximations, only an algebraic sum is carried out. For parallel polarization, the vertical and horizontal components of electric field are compared. After that, a comparison between these two manners is made, and an analysis of the error versus r distance is provided.
2009 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2009
In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction f... more In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction for a LOS microcellular model. Our street waveguide model congregates the derivation of a precise ray-geometry, strict polarization, an improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.
2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011), 2011
In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved ... more In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern
IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics, 2005., 2005
ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban ch... more ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban characteristics as well as its variations and comparisons. The three-dimensional waveguide contains transmitting and receiving antennas. Four kinds of generalization for reflections on the lateral borders of a three-dimensional (3D) waveguide are discussed.
2006 10th IEEE Singapore International Conference on Communication Systems, 2006
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a multislit waveguide channel. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed.
IEEE International Symposium on Communications and Information Technology, 2004. ISCIT 2004., 2004
In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis o... more In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields)
2006 International Telecommunications Symposium, 2006
In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model... more In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model in UHF band. For such model the street is modeled as a 3D multislit waveguide and an ideal dipole is assumed to be the transmitting aerial. Horizontal and vertical polarizations are investigated in terms of direct incidence, ground reflection, multiple reflections on the lateral
Applied Mathematical Modelling, 2012
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a deterministic multislit waveguide channel, according to its database, and vectorial analysis is also taken into account. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed. Comparisons provided with measured data show that the models proposed can be very useful tools toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved ... more In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a deterministic multislit waveguide channel, according to its database, and vectorial analysis is also taken into account. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed. Comparisons provided with measured data show that the models proposed can be very useful tools toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction f... more In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction for a LOS microcellular model. Our street waveguide model congregates the derivation of a precise ray-geometry, strict polarization, an improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a multislit waveguide channel. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed.
ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Eart... more ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Earth, which consists of a ray that arrive at the receptor along a straight line and of a ray that arrive at the receptor after a ground reflection. This model is analyzed throughout two manners for parallel polarization: with and without approximations regarding to the summation of the electric fields at the point of reception. For the model analyzed without approximations, an ideal dipole is assumed as a transmitting aerial and a vectorial analysis is accounted. For the model analyzed with approximations, only an algebraic sum is carried out. For parallel polarization, the vertical and horizontal components of electric field are compared. After that, a comparison between these two manners is made, and an analysis of the error versus r distance is provided.
In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis o... more In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields)
ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban ch... more ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban characteristics as well as its variations and comparisons. The three-dimensional waveguide contains transmitting and receiving antennas. Four kinds of generalization for reflections on the lateral borders of a three-dimensional (3D) waveguide are discussed.
In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model... more In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model in UHF band. For such model the street is modeled as a 3D multislit waveguide and an ideal dipole is assumed to be the transmitting aerial. Horizontal and vertical polarizations are investigated in terms of direct incidence, ground reflection, multiple reflections on the lateral
Revista de Ensino de Engenharia
Este estudo apresenta uma análise do efeito estroboscópico: uma abordagem didática para ensinar o... more Este estudo apresenta uma análise do efeito estroboscópico: uma abordagem didática para ensinar o fenômeno de aliasing causado pela subamostragem para alunos de graduação em Engenharia de Computação. O artigo em si é um resultado concreto da metodologia e procedimentos utilizados para ensinar o assunto supramencionado. Uma análise matemática do efeito estroboscópico é realizada e, então, as frequências existentes nesse fenômeno por meio do giro de um ventilador iluminado por uma lâmpada estroboscópica são relacionadas. Além disso, dada a importância da visão humana neste contexto, os diferentes efeitos percebidos à luz do processo de amostragem são explicados. Para representar o movimento da fita vermelha colada em uma das hélices de um ventilador, um simulador foi desenvolvido, cuja visualização do fenômeno é possível, considerando as variáveis levadas em conta na etapa de modelagem matemática. Um conjunto de testes foi feito em cada intervalo designado, a fim de correlacionar as faixas de frequência obtidas analiticamente com o movimento percebido pelo olho humano, associando ambos e validando a modelagem. Com os resultados deste estudo é possível compreender a influência da frequência no processo de amostragem, bem como suas principais implicações, tais como o fenômeno aliasing: o resultado do processo de subamostragem.
In this work we present a vectorial analysis of the two-ray model, as well as a vectorial analysi... more In this work we present a vectorial analysis of the two-ray model, as well as a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the analysis of the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields) and non-approximated analysis (considering dipole's gain and vectorial analysis) is provided as well as an analysis of the error versus r distance. A comparison between vertical and horizontal components of the electric field is also carried out. Regarding the street model, the street is modeled as a multislit waveguide, and horizontal and vertical polarizations are investigated. As in the tworay model, a comparison between the approximated and non-approximated analysis is provided as well as a comparison between the total field and the field due to lateral reflections only. Still for the street model, slits are inserted and comparisons and analyses are made. Comparisons provided show that a vectorial and gain analysis can be a very useful tool toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
The Ninth International Conference onCommunications Systems, 2004. ICCS 2004., 2004
ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Eart... more ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Earth, which consists of a ray that arrive at the receptor along a straight line and of a ray that arrive at the receptor after a ground reflection. This model is analyzed throughout two manners for parallel polarization: with and without approximations regarding to the summation of the electric fields at the point of reception. For the model analyzed without approximations, an ideal dipole is assumed as a transmitting aerial and a vectorial analysis is accounted. For the model analyzed with approximations, only an algebraic sum is carried out. For parallel polarization, the vertical and horizontal components of electric field are compared. After that, a comparison between these two manners is made, and an analysis of the error versus r distance is provided.
2009 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC), 2009
In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction f... more In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction for a LOS microcellular model. Our street waveguide model congregates the derivation of a precise ray-geometry, strict polarization, an improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.
2011 SBMO/IEEE MTT-S International Microwave and Optoelectronics Conference (IMOC 2011), 2011
In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved ... more In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern
IEEE/ACES International Conference on Wireless Communications and Applied Computational Electromagnetics, 2005., 2005
ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban ch... more ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban characteristics as well as its variations and comparisons. The three-dimensional waveguide contains transmitting and receiving antennas. Four kinds of generalization for reflections on the lateral borders of a three-dimensional (3D) waveguide are discussed.
2006 10th IEEE Singapore International Conference on Communication Systems, 2006
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a multislit waveguide channel. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed.
IEEE International Symposium on Communications and Information Technology, 2004. ISCIT 2004., 2004
In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis o... more In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields)
2006 International Telecommunications Symposium, 2006
In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model... more In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model in UHF band. For such model the street is modeled as a 3D multislit waveguide and an ideal dipole is assumed to be the transmitting aerial. Horizontal and vertical polarizations are investigated in terms of direct incidence, ground reflection, multiple reflections on the lateral
Applied Mathematical Modelling, 2012
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a deterministic multislit waveguide channel, according to its database, and vectorial analysis is also taken into account. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed. Comparisons provided with measured data show that the models proposed can be very useful tools toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved ... more In this paper we propose a three-dimensional (3D) extension of the two-dimensional (2D) improved heuristic diffraction coefficient and investigate the diffraction contribution using a 3D UTD wedge diffraction for a LOS microcellular model. Our 3D street waveguide model congregates the derivation of a 3D precise ray-geometry, strict polarization, a 3D improved heuristic diffraction coefficient, and vectorial and field radiation pattern
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a deterministic multislit waveguide channel, according to its database, and vectorial analysis is also taken into account. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed. Comparisons provided with measured data show that the models proposed can be very useful tools toward increasing theoretical analysis in spite of empirical analysis in the field of prediction.
In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction f... more In this paper we investigate in detail the diffraction contribution using UTD wedge diffraction for a LOS microcellular model. Our street waveguide model congregates the derivation of a precise ray-geometry, strict polarization, an improved heuristic diffraction coefficient, and vectorial and field radiation pattern analyses.
In this paper we present theoretical models for microcellular communications at UHF and microwave... more In this paper we present theoretical models for microcellular communications at UHF and microwave frequencies. For rural microcells, a vectorial analysis of the two-ray model is carried out, and comparisons between the developed model and measurements reported in rural areas of New Jersey and San Francisco Bay are provided. For urban microcells, the street is three-dimensionally modeled as a multislit waveguide channel. For the 3D street model, comparisons in good agreement with measurements reported in New York City are performed.
ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Eart... more ABSTRACT In this work we present an UHF band two-ray model for elevated antennas over a flat Earth, which consists of a ray that arrive at the receptor along a straight line and of a ray that arrive at the receptor after a ground reflection. This model is analyzed throughout two manners for parallel polarization: with and without approximations regarding to the summation of the electric fields at the point of reception. For the model analyzed without approximations, an ideal dipole is assumed as a transmitting aerial and a vectorial analysis is accounted. For the model analyzed with approximations, only an algebraic sum is carried out. For parallel polarization, the vertical and horizontal components of electric field are compared. After that, a comparison between these two manners is made, and an analysis of the error versus r distance is provided.
In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis o... more In this work we present a vectorial analysis of the two-ray model, as well a vectorial analysis of the whole street waveguide model in the UHF band. For both, an ideal dipole is assumed to be the transmitting aerial. For the two-ray model, parallel polarization is investigated and a comparison between the approximated analysis (only algebraic sum of the fields)
ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban ch... more ABSTRACT The purpose of this paper is to derive a three-dimensional waveguide model with urban characteristics as well as its variations and comparisons. The three-dimensional waveguide contains transmitting and receiving antennas. Four kinds of generalization for reflections on the lateral borders of a three-dimensional (3D) waveguide are discussed.
In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model... more In this work we present a vectorial analysis of the three dimensional (3D) street waveguide model in UHF band. For such model the street is modeled as a 3D multislit waveguide and an ideal dipole is assumed to be the transmitting aerial. Horizontal and vertical polarizations are investigated in terms of direct incidence, ground reflection, multiple reflections on the lateral