The Experts below are selected from a list of 5463 Experts worldwide ranked by ideXlab platform
Achmad Munir - One of the best experts on this subject based on the ideXlab platform.
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Cylindrical Coordinate System-based FDTD method for analysis of THz circular waveguide coated by dielectric material
2016 22nd Asia-Pacific Conference on Communications (APCC), 2016Co-Authors: Antrisha Daneraici Setiawan, Achmad MunirAbstract:This paper presents the analysis of reflectivity and transmissivity for terahertz (THz) circular waveguide coated by dielectric material using Cylindrical Coordinate System-based finite difference time domain (FDTD) method. The analysis is conducted by discretizing a model of THz circular waveguide with the radius of 50μm and the length of 250μm. The scattering parameters in term of reflectivity and transmissivity are extracted from the electric fields obtained at different observation planes. Some scenarios in the analysis of reflectivity and transmissivity are applied by varying the thickness of coated dielectric material inside the circular waveguide compared to the hollow circular waveguide. Others scenarios are carried out by introducing some values of conductivity into the dielectric material. From the results, it is shown that resonant frequencies of circular waveguide coated by dielectric material in transverse electric (TE) mode are lower than the hollow waveguide. It also shows that the circular waveguide coated by dielectric material with the thickness of 7.5μm and the conductivity of 250S/m has better transmissivity than the hollow circular waveguide.
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APCC - Cylindrical Coordinate System-based FDTD method for analysis of THz circular waveguide coated by dielectric material
2016 22nd Asia-Pacific Conference on Communications (APCC), 2016Co-Authors: Antrisha Daneraici Setiawan, Achmad MunirAbstract:This paper presents the analysis of reflectivity and transmissivity for terahertz (THz) circular waveguide coated by dielectric material using Cylindrical Coordinate System-based finite difference time domain (FDTD) method. The analysis is conducted by discretizing a model of THz circular waveguide with the radius of 50μm and the length of 250μm. The scattering parameters in term of reflectivity and transmissivity are extracted from the electric fields obtained at different observation planes. Some scenarios in the analysis of reflectivity and transmissivity are applied by varying the thickness of coated dielectric material inside the circular waveguide compared to the hollow circular waveguide. Others scenarios are carried out by introducing some values of conductivity into the dielectric material. From the results, it is shown that resonant frequencies of circular waveguide coated by dielectric material in transverse electric (TE) mode are lower than the hollow waveguide. It also shows that the circular waveguide coated by dielectric material with the thickness of 7.5μm and the conductivity of 250S/m has better transmissivity than the hollow circular waveguide.
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Scattering parameters extraction of dielectric loaded circular waveguide using Cylindrical Coordinate System-based FDTD method
2015 International Seminar on Intelligent Technology and Its Applications (ISITIA), 2015Co-Authors: Ershad Junus Amin, Achmad MunirAbstract:The scattering parameters of circular waveguide loaded with dielectric material is proposed to be extracted using a method of finite-difference time-domain (FDTD) based on Cylindrical Coordinate System. The extraction of scattering parameters, i.e. reflection coefficient (S11) and transmission coefficient (S21), are performed by the electric fields obtained on different observation planes closed to the dielectric material. Some isotropic dielectric material which partially and fully loaded circular waveguide are included in the analysis. To validate the result of FDTD method, another analysis is carried out by using finite element method (FEM) commercialized software. Furthermore, the FDTD method is also applied to analysis a circular waveguide loaded with some anisotropic dielectric material. From the result, it shows that the proposed FDTD method has a good agreement qualitatively compared to the commercialized software with some discrepancy on the extraction result less than 3% for isotropic dielectric material loaded circular waveguide. Meanwhile, there is no result comparison for anisotropic dielectric material loaded circular waveguide due to an inability of commercialized software to perform a simulation in Cylindrical Coordinate System.
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Cylindrical Coordinate System-based full wave FDTD computation for resonant frequency calculation of circular cavity resonator
2015 1st International Conference on Wireless and Telematics (ICWT), 2015Co-Authors: Achmad Munir, Biru Tutur RanumAbstract:In this paper, a full wave finite difference time domain (FDTD) computation method based on Cylindrical Coordinate System is proposed for calculating the resonant frequency of circular cavity resonator. The use of FDTD method with Cylindrical Coordinate System instead of Cartesian Coordinate System is considered due to the geometry shape of analyzed structure, i.e. circular cavity resonator. In the computation, a hollow circular cavity resonator made of perfect conductor with the radius of 50mm and length of 100mm is discretized based on Cylindrical Coordinate System and numerically computed to determine its resonant frequencies. To verify the proposed method, the theoretical approach for the cavity is carried out by calculating its resonant frequencies for correspondent resonance mode. In addition, a simulation for determining resonant frequencies of the cavity is also conducted using finite element method (FEM) commercialized software. It shows that the FDTD computation result demonstrates an acceptable accuracy compared to the theoretical approach with the discrepancy less than 5% although it is worse than the result of FEM commercialized software.
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Computational approach for resonant frequency calculation of coaxial cavity resonator using Cylindrical Coordinate System-based FDTD method
2015 International Conference on Quality in Research (QiR), 2015Co-Authors: Achmad Munir, EdwarAbstract:A computational approach for resonant frequency calculation of coaxial cavity resonator using a Cylindrical Coordinate System-based finite difference time domain (FDTD) method is presented. Due to the geometry shape of analyzed structure, i.e. coaxial cavity resonator, the use of FDTD method with Cylindrical Coordinate System is chosen instead of Cartesian Coordinate System. A coaxial cavity resonator made of perfect conductor with outer diameter of 100mm, inner diameter of 40mm and length of 150mm is modeled and discretized based on FDTD notation and then numerically computed to determine its resonant frequencies in the frequency range of 1–5GHz. Moreover, a simulation using finite element method (FEM) commercialized software is also conducted to determine resonant frequencies of the resonator for comparison. From the results, it shows that the proposed FDTD approach demonstrates the capability to determine resonant frequencies of coaxial cavity resonator with an acceptable accuracy compared to the FEM commercialized software in the maximum discrepancy around than 3%.
Antrisha Daneraici Setiawan - One of the best experts on this subject based on the ideXlab platform.
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Cylindrical Coordinate System-based FDTD method for analysis of THz circular waveguide coated by dielectric material
2016 22nd Asia-Pacific Conference on Communications (APCC), 2016Co-Authors: Antrisha Daneraici Setiawan, Achmad MunirAbstract:This paper presents the analysis of reflectivity and transmissivity for terahertz (THz) circular waveguide coated by dielectric material using Cylindrical Coordinate System-based finite difference time domain (FDTD) method. The analysis is conducted by discretizing a model of THz circular waveguide with the radius of 50μm and the length of 250μm. The scattering parameters in term of reflectivity and transmissivity are extracted from the electric fields obtained at different observation planes. Some scenarios in the analysis of reflectivity and transmissivity are applied by varying the thickness of coated dielectric material inside the circular waveguide compared to the hollow circular waveguide. Others scenarios are carried out by introducing some values of conductivity into the dielectric material. From the results, it is shown that resonant frequencies of circular waveguide coated by dielectric material in transverse electric (TE) mode are lower than the hollow waveguide. It also shows that the circular waveguide coated by dielectric material with the thickness of 7.5μm and the conductivity of 250S/m has better transmissivity than the hollow circular waveguide.
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APCC - Cylindrical Coordinate System-based FDTD method for analysis of THz circular waveguide coated by dielectric material
2016 22nd Asia-Pacific Conference on Communications (APCC), 2016Co-Authors: Antrisha Daneraici Setiawan, Achmad MunirAbstract:This paper presents the analysis of reflectivity and transmissivity for terahertz (THz) circular waveguide coated by dielectric material using Cylindrical Coordinate System-based finite difference time domain (FDTD) method. The analysis is conducted by discretizing a model of THz circular waveguide with the radius of 50μm and the length of 250μm. The scattering parameters in term of reflectivity and transmissivity are extracted from the electric fields obtained at different observation planes. Some scenarios in the analysis of reflectivity and transmissivity are applied by varying the thickness of coated dielectric material inside the circular waveguide compared to the hollow circular waveguide. Others scenarios are carried out by introducing some values of conductivity into the dielectric material. From the results, it is shown that resonant frequencies of circular waveguide coated by dielectric material in transverse electric (TE) mode are lower than the hollow waveguide. It also shows that the circular waveguide coated by dielectric material with the thickness of 7.5μm and the conductivity of 250S/m has better transmissivity than the hollow circular waveguide.
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Resonant frequency computation of dielectric material loaded circular waveguide using Cylindrical Coordinate System-based FDTD method
2015 International Conference on Electrical Engineering and Informatics (ICEEI), 2015Co-Authors: Antrisha Daneraici Setiawan, Hardi Nusantara, Achmad MunirAbstract:In this paper, a Cylindrical Coordinate System-based finite difference time domain (FDTD) method is proposed for resonant frequency computation of dielectric material loaded circular waveguide. The computation is carried out by discretizing a model of circular waveguide resonator which has the radius of 10.12mm and the length of 60mm using FDTD notation and numerically computed to determine its resonant frequency in transverse electric (TE) mode. Some scenarios are applied for loading the waveguide by dielectric materials to analyze its resonant frequency to be compared with the hollow circular waveguide. From the results, it is shown that the TE mode resonant frequency for loaded circular waveguide is lower than of hollow circular waveguide which satisfies the numerical prediction. Meanwhile, from the scenario of circular waveguide partially loaded with dielectric material which is coated from outer region in a certain depth, it is found that the resonant frequency varies depending on the depth of dielectric material or on the volume proportion of dielectric material in the waveguide. The result shows when the proportion of dielectric material is 36% the lower resonant frequency is similar with the waveguide fully loaded with dielectric material.
N. Okiyama - One of the best experts on this subject based on the ideXlab platform.
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A new formulation of visual servoing based on Cylindrical Coordinate System
IEEE Transactions on Robotics, 2005Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using two-dimensional visual data. However, it is well known that the classical visual servoing based on the Cartesian Coordinate System has one crucial problem, that the camera moves backward at infinity, in case that the camera motion from the initial to desired poses is a pure rotation of 1800 around the optical axis. This paper proposes a new formulation of visual servoing, based on a Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on the Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between initial and desired image-plane positions of feature points.
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a new formulation of visual servoing based on Cylindrical Coordinate System with shiftable origin
Intelligent Robots and Systems, 2002Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using 2D visual data. However, it is well known that the classical visual servoing based on Cartesian Coordinate System has one crucial problem that the camera moves backward at infinity in case that the camera motion from the initial to desired poses is a pure rotation of 180 degrees around the optical axis. This paper proposes a new formulation of visual servoing based on Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between current and desired image-plane positions of feature points.
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IROS - A new formulation of visual servoing based on Cylindrical Coordinate System with shiftable origin
IEEE RSJ International Conference on Intelligent Robots and System, 1Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using 2D visual data. However, it is well known that the classical visual servoing based on Cartesian Coordinate System has one crucial problem that the camera moves backward at infinity in case that the camera motion from the initial to desired poses is a pure rotation of 180 degrees around the optical axis. This paper proposes a new formulation of visual servoing based on Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between current and desired image-plane positions of feature points.
Xiaohan Sun - One of the best experts on this subject based on the ideXlab platform.
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vector analysis of bending waveguides by using a modified finite difference method in a local Cylindrical Coordinate System
Optics Express, 2012Co-Authors: Jinbiao Xiao, Xiaohan SunAbstract:A vector mode solver for bending waveguides by using a modified finite-difference (FD) method is developed in a local Cylindrical Coordinate System, where the perfectly matched layer absorbing boundary conditions are incorporated. Utilizing Taylor series expansion technique and continuity condition of the longitudinal field components, a standard matrix eigenvalue equation without the averaged index approximation approach for dealing with the discrete points neighboring the dielectric interfaces is obtained. Complex effective indexes and field distributions of leaky modes for a typical rib bending waveguide and a silicon wire bend are presented, and solutions accord well with those from the film mode matching method, which shows the validity and utility of the established method.
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Full-vectorial analysis of bending silicon wires by using an improved finite-difference method
Asia Communications and Photonics Conference, 2012Co-Authors: Jinbiao Xiao, Xiaohan SunAbstract:An improved finite-difference scheme in a local Cylindrical Coordinate System is proposed for full-vectorial analysis of bending silicon wires. Both the complex effective indexes and field distributions of the leaky modes are presented.
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Full-Vectorial Mode Solver for Bending Waveguides Using Multidomain Pseudospectral Method in a Cylindrical Coordinate System
IEEE Photonics Technology Letters, 2009Co-Authors: Jinbiao Xiao, Ningfeng Bai, Xu Liu, Xiaohan SunAbstract:A full-vectorial mode solver for bending waveguides using a spectral collocation method in a local Cylindrical Coordinate System is described. The perfectly matched layers' absorption boundary conditions are incorporated into the present method for effectively demonstrating the leaky nature of the bending waveguides. The domain decomposition technique is utilized for improving the computational accuracy and stability. A bending rib waveguide with high index contrast is considered as a numerical example to validate the established method.
M. Iwatsuki - One of the best experts on this subject based on the ideXlab platform.
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A new formulation of visual servoing based on Cylindrical Coordinate System
IEEE Transactions on Robotics, 2005Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using two-dimensional visual data. However, it is well known that the classical visual servoing based on the Cartesian Coordinate System has one crucial problem, that the camera moves backward at infinity, in case that the camera motion from the initial to desired poses is a pure rotation of 1800 around the optical axis. This paper proposes a new formulation of visual servoing, based on a Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on the Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between initial and desired image-plane positions of feature points.
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a new formulation of visual servoing based on Cylindrical Coordinate System with shiftable origin
Intelligent Robots and Systems, 2002Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using 2D visual data. However, it is well known that the classical visual servoing based on Cartesian Coordinate System has one crucial problem that the camera moves backward at infinity in case that the camera motion from the initial to desired poses is a pure rotation of 180 degrees around the optical axis. This paper proposes a new formulation of visual servoing based on Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between current and desired image-plane positions of feature points.
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IROS - A new formulation of visual servoing based on Cylindrical Coordinate System with shiftable origin
IEEE RSJ International Conference on Intelligent Robots and System, 1Co-Authors: M. Iwatsuki, N. OkiyamaAbstract:Image-based visual servoing is a flexible and robust technique to control a robot and guide it to a desired position only by using 2D visual data. However, it is well known that the classical visual servoing based on Cartesian Coordinate System has one crucial problem that the camera moves backward at infinity in case that the camera motion from the initial to desired poses is a pure rotation of 180 degrees around the optical axis. This paper proposes a new formulation of visual servoing based on Cylindrical Coordinate System that can shift the position of the origin. The proposed approach can interpret from a pure rotation around an arbitrary axis to the proper camera rotational motion. It is shown that this formulation contains the classical approach based on Cartesian Coordinate System as an extreme case with the origin located at infinity. Furthermore, we propose a decision method of the origin-shift parameters by estimating a rotational motion from the differences between current and desired image-plane positions of feature points.
