This document presents a technique for estimating parameters of a deployable mesh reflector antenna using 3D coordinate data and least squares fitting. It involves determining the unknown coefficients of the general quadratic surface equation that best fits the 3D points. The shape of the surface is then estimated as an elliptic paraboloid based on its invariants. Key parameters of the elliptic paraboloid like the focal length are then determined by reconstructing the surface in its standard form based on the estimated coefficients and orientations. Estimating these parameters at different stages of deployment testing can help validate the stability of the antenna surface and placement of its feed.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Perimetric Complexity of Binary Digital ImagesRSARANYADEVI
Perimetric complexity is a measure of the complexity of binary pictures. It is defined as the sum of inside and outside perimeters of the foreground, squared, divided by the foreground area, divided by . Difficulties arise when this definition is applied to digital images composed of binary pixels. In this article we identify these problems and propose solutions. Perimetric complexity is often used as a measure of visual complexity, in which case it should take into account the limited resolution of the visual system. We propose a measure of visual perimetric complexity that meets this requirement.
COMPARATIVE STUDY ON BENDING LOSS BETWEEN DIFFERENT S-SHAPED WAVEGUIDE BENDS ...cscpconf
Bending loss in the waveguide as well as the leakage losses and absorption losses along with a comparative study among different types of S-shaped bend structures has been computed with
the help of a simple matrix method.This method needs simple 2×2 matrix multiplication. The
effective-index profile of the bended waveguide is then transformed to an equivalent straight
waveguide with the help of a suitable mapping technique and is partitioned into large number of thin sections of different refractive indices. The transfer matrix of the two adjacent layers will be a 2×2 matrix relating the field components in adjacent layers. The total transfer matrix is
obtained through multiplication of all these transfer matrices. The excitation efficiency of the
wave in the guiding layer shows a Lorentzian profile. The power attenuation coefficient of the
bent waveguide is the full-width-half-maximum (FWHM) of this peak .Now the transition losses and pure bending losses can be computed from these FWHM datas.The computation technique
is quite fast and it is applicable for any waveguide having different parameters and wavelength of light for both polarizations(TE and TM)
Chapter summary and solutions to end-of-chapter exercises for "Data Visualization: Principles and Practice" book by Alexandru C. Telea
This chapter lays out a discussion on discrete data representation, continuous data sampling and re- construction. Fundamental differences between continuous (sampled) and discrete data are outlined. It introduces basic functions, discrete meshes and cells as means of constructing piecewise continuous approximations from sampled data. One learns about various types of datasets commonly used in the visualization practice: their advantages, limitations and constraints. This chapter gives an understanding of various trade-offs involved in the choice of a dataset for a given visualization application while focuses on efficiency of implementing the most commonly used datasets presented with cell types in d ∈ [0, 3] dimensions.
Image Restoration and Denoising By Using Nonlocally Centralized Sparse Repres...IJERA Editor
Due to the degradation of observed image the noisy, blurred, Distorted image can be occurred .for restoring image information we propose the sparse representations by conventional modelsmay not be accurate enough for a faithful reconstruction of the original image. To improve the performance of sparse representation-based image restoration,In this method the sparse coding noise is added for image restoration, due to this image restoration the sparse coefficients of original image can be detected. The so-called nonlocally centralized sparse representation (NCSR) model is as simple as the standard sparse representation model,for denoising the image here we use the Histogram clipping method by using histogram based sparse representation effectively reduce the noise.and also implement the TMR filter for Quality image.various types of image restoration problems, including denoising, deblurring and super-resolution, validate the generality and state-of-the-art performance of the proposed algorithm.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Perimetric Complexity of Binary Digital ImagesRSARANYADEVI
Perimetric complexity is a measure of the complexity of binary pictures. It is defined as the sum of inside and outside perimeters of the foreground, squared, divided by the foreground area, divided by . Difficulties arise when this definition is applied to digital images composed of binary pixels. In this article we identify these problems and propose solutions. Perimetric complexity is often used as a measure of visual complexity, in which case it should take into account the limited resolution of the visual system. We propose a measure of visual perimetric complexity that meets this requirement.
COMPARATIVE STUDY ON BENDING LOSS BETWEEN DIFFERENT S-SHAPED WAVEGUIDE BENDS ...cscpconf
Bending loss in the waveguide as well as the leakage losses and absorption losses along with a comparative study among different types of S-shaped bend structures has been computed with
the help of a simple matrix method.This method needs simple 2×2 matrix multiplication. The
effective-index profile of the bended waveguide is then transformed to an equivalent straight
waveguide with the help of a suitable mapping technique and is partitioned into large number of thin sections of different refractive indices. The transfer matrix of the two adjacent layers will be a 2×2 matrix relating the field components in adjacent layers. The total transfer matrix is
obtained through multiplication of all these transfer matrices. The excitation efficiency of the
wave in the guiding layer shows a Lorentzian profile. The power attenuation coefficient of the
bent waveguide is the full-width-half-maximum (FWHM) of this peak .Now the transition losses and pure bending losses can be computed from these FWHM datas.The computation technique
is quite fast and it is applicable for any waveguide having different parameters and wavelength of light for both polarizations(TE and TM)
Chapter summary and solutions to end-of-chapter exercises for "Data Visualization: Principles and Practice" book by Alexandru C. Telea
This chapter lays out a discussion on discrete data representation, continuous data sampling and re- construction. Fundamental differences between continuous (sampled) and discrete data are outlined. It introduces basic functions, discrete meshes and cells as means of constructing piecewise continuous approximations from sampled data. One learns about various types of datasets commonly used in the visualization practice: their advantages, limitations and constraints. This chapter gives an understanding of various trade-offs involved in the choice of a dataset for a given visualization application while focuses on efficiency of implementing the most commonly used datasets presented with cell types in d ∈ [0, 3] dimensions.
Image Restoration and Denoising By Using Nonlocally Centralized Sparse Repres...IJERA Editor
Due to the degradation of observed image the noisy, blurred, Distorted image can be occurred .for restoring image information we propose the sparse representations by conventional modelsmay not be accurate enough for a faithful reconstruction of the original image. To improve the performance of sparse representation-based image restoration,In this method the sparse coding noise is added for image restoration, due to this image restoration the sparse coefficients of original image can be detected. The so-called nonlocally centralized sparse representation (NCSR) model is as simple as the standard sparse representation model,for denoising the image here we use the Histogram clipping method by using histogram based sparse representation effectively reduce the noise.and also implement the TMR filter for Quality image.various types of image restoration problems, including denoising, deblurring and super-resolution, validate the generality and state-of-the-art performance of the proposed algorithm.
Chapter summary and solutions to end-of-chapter exercises for "Data Visualization: Principles and Practice" book by Alexandru C. Telea
Chapter provides an overview of a number of methods for visualizing tensor data. It explains principal component analysis as a technique used to process a tensor matrix and extract from it information that can directly be used in its visualization. It forms a fundamental part of many tensor data processing and visualization algorithms. Section 7.4 shows how the results of the principal component analysis can be visualized using the simple color-mapping techniques. Next parts of the chapter explain how same data can be visualized using tensor glyphs, and streamline-like visualization techniques.
In contrast to Slicer, which is a more general framework for analyzing and visualizing 3D slice-based data volumes, the Diffusion Toolkit focuses on DT-MRI datasets, and thus offers more extensive and easier to use options for fiber tracking.
Geoid height determination is one of the major problems of geodesy because usage of satellite
techniques in geodesy isgetting increasing. Geoid heights can be determined using different methods according
to the available data. Soft computing methods such as Fuzzy logic and neural networks became so popular that
they are used to solve many engineering problems. Fuzzy logic theory and later developments in uncertainty
assessment have enabled us to develop more precise models for our requirements. In this study, How to
construct the best fuzzy model is examined. For this purpose, three different data sets were taken and two
different kinds (two inpust one output and three inputs one output) fuzzy model were formed for the calculation
of geoid heights in Istanbul (Turkey). The Fuzzy models results of these were compared with geoid heights
obtained by GPS/levelling methods. The fuzzy approximation models were tested on the test points.
FINGERPRINT CLASSIFICATION BASED ON ORIENTATION FIELDijesajournal
ABSTRACT
This paper introduces an effective method of fingerprint classification based on discriminative feature gathering from orientation field. A nonlinear support vector machines (SVMs) is adopted for the classification. The orientation field is estimated through a pixel-Wise gradient descent method and the percentage of directional block classes is estimated. These percentages are classified into four-dimensional vector considered as a good feature that can be combined with an accurate singular point to classify the fingerprint into one of five classes. This method shows high classification accuracy relative to other spatial domain classifiers.
ALEXANDER FRACTIONAL INTEGRAL FILTERING OF WAVELET COEFFICIENTS FOR IMAGE DEN...sipij
The present paper, proposes an efficient denoising algorithm which works well for images corrupted with
Gaussian and speckle noise. The denoising algorithm utilizes the alexander fractional integral filter which
works by the construction of fractional masks window computed using alexander polynomial. Prior to the
application of the designed filter, the corrupted image is decomposed using symlet wavelet from which only
the horizontal, vertical and diagonal components are denoised using the alexander integral filter.
Significant increase in the reconstruction quality was noticed when the approach was applied on the
wavelet decomposed image rather than applying it directly on the noisy image. Quantitatively the results
are evaluated using the peak signal to noise ratio (PSNR) which was 30.8059 on an average for images
corrupted with Gaussian noise and 36.52 for images corrupted with speckle noise, which clearly
outperforms the existing methods.
linear feature extraction from topographic maps using energy density and shea...Abhiram Subhagan
linear feature extraction from topographic maps using energy density and shear transform
this paper is based on MATLAB to extract linear features such as roads and rivers from geographic maps
Here is a new 9-point scheme for finite difference solution of acoustic waves in frequency domain. The algorithm honors both accuracy and computational efficiency.
Ill-posedness formulation of the emission source localization in the radio- d...Ahmed Ammar Rebai PhD
To contact the authors : tarek.salhi@gmail.com and ahmed.rebai2@gmail.com
In the field of radio detection in astroparticle physics, many studies have shown the strong dependence of the solution of the radio-transient sources localization problem (the radio-shower time of arrival on antennas) such solutions are purely numerical artifacts. Based on a detailed analysis of some already published results of radio-detection experiments like : CODALEMA 3 in France, AERA in Argentina and TREND in China, we demonstrate the ill-posed character of this problem in the sens of Hadamard. Two approaches have been used as the existence of solutions degeneration and the bad conditioning of the mathematical formulation problem. A comparison between experimental results and simulations have been made, to highlight the mathematical studies. Many properties of the non-linear least square function are discussed such as the configuration of the set of solutions and the bias.
Chapter summary and solutions to end-of-chapter exercises for "Data Visualization: Principles and Practice" book by Alexandru C. Telea
Chapter provides an overview of a number of methods for visualizing tensor data. It explains principal component analysis as a technique used to process a tensor matrix and extract from it information that can directly be used in its visualization. It forms a fundamental part of many tensor data processing and visualization algorithms. Section 7.4 shows how the results of the principal component analysis can be visualized using the simple color-mapping techniques. Next parts of the chapter explain how same data can be visualized using tensor glyphs, and streamline-like visualization techniques.
In contrast to Slicer, which is a more general framework for analyzing and visualizing 3D slice-based data volumes, the Diffusion Toolkit focuses on DT-MRI datasets, and thus offers more extensive and easier to use options for fiber tracking.
Geoid height determination is one of the major problems of geodesy because usage of satellite
techniques in geodesy isgetting increasing. Geoid heights can be determined using different methods according
to the available data. Soft computing methods such as Fuzzy logic and neural networks became so popular that
they are used to solve many engineering problems. Fuzzy logic theory and later developments in uncertainty
assessment have enabled us to develop more precise models for our requirements. In this study, How to
construct the best fuzzy model is examined. For this purpose, three different data sets were taken and two
different kinds (two inpust one output and three inputs one output) fuzzy model were formed for the calculation
of geoid heights in Istanbul (Turkey). The Fuzzy models results of these were compared with geoid heights
obtained by GPS/levelling methods. The fuzzy approximation models were tested on the test points.
FINGERPRINT CLASSIFICATION BASED ON ORIENTATION FIELDijesajournal
ABSTRACT
This paper introduces an effective method of fingerprint classification based on discriminative feature gathering from orientation field. A nonlinear support vector machines (SVMs) is adopted for the classification. The orientation field is estimated through a pixel-Wise gradient descent method and the percentage of directional block classes is estimated. These percentages are classified into four-dimensional vector considered as a good feature that can be combined with an accurate singular point to classify the fingerprint into one of five classes. This method shows high classification accuracy relative to other spatial domain classifiers.
ALEXANDER FRACTIONAL INTEGRAL FILTERING OF WAVELET COEFFICIENTS FOR IMAGE DEN...sipij
The present paper, proposes an efficient denoising algorithm which works well for images corrupted with
Gaussian and speckle noise. The denoising algorithm utilizes the alexander fractional integral filter which
works by the construction of fractional masks window computed using alexander polynomial. Prior to the
application of the designed filter, the corrupted image is decomposed using symlet wavelet from which only
the horizontal, vertical and diagonal components are denoised using the alexander integral filter.
Significant increase in the reconstruction quality was noticed when the approach was applied on the
wavelet decomposed image rather than applying it directly on the noisy image. Quantitatively the results
are evaluated using the peak signal to noise ratio (PSNR) which was 30.8059 on an average for images
corrupted with Gaussian noise and 36.52 for images corrupted with speckle noise, which clearly
outperforms the existing methods.
linear feature extraction from topographic maps using energy density and shea...Abhiram Subhagan
linear feature extraction from topographic maps using energy density and shear transform
this paper is based on MATLAB to extract linear features such as roads and rivers from geographic maps
Here is a new 9-point scheme for finite difference solution of acoustic waves in frequency domain. The algorithm honors both accuracy and computational efficiency.
Ill-posedness formulation of the emission source localization in the radio- d...Ahmed Ammar Rebai PhD
To contact the authors : tarek.salhi@gmail.com and ahmed.rebai2@gmail.com
In the field of radio detection in astroparticle physics, many studies have shown the strong dependence of the solution of the radio-transient sources localization problem (the radio-shower time of arrival on antennas) such solutions are purely numerical artifacts. Based on a detailed analysis of some already published results of radio-detection experiments like : CODALEMA 3 in France, AERA in Argentina and TREND in China, we demonstrate the ill-posed character of this problem in the sens of Hadamard. Two approaches have been used as the existence of solutions degeneration and the bad conditioning of the mathematical formulation problem. A comparison between experimental results and simulations have been made, to highlight the mathematical studies. Many properties of the non-linear least square function are discussed such as the configuration of the set of solutions and the bias.
Design of a Selective Filter based on 2D Photonic Crystals Materials IJECEIAES
Two dimensional finite differences temporal domain (2D-FDTD) numerical simulations are performed in cartesian coordinate system to determine the dispersion diagrams of transverse electric (TE) of a two-dimension photonic crystal (PC) with triangular lattice. The aim of this work is to design a filter with maximum spectral response close to the frequency 1.55 μm. To achieve this frequency, selective filters PC are formed by combination of three waveguides W 1 K A wherein the air holes have of different normalized radii respectively r 1 /a=0.44, r 2 /a=0.288 and r /a= 0.3292 (a: is the periodicity of the lattice with value 0.48 μm). Best response is obtained when we insert three small cylindrical cavities (with normalized radius of 0.17) between the two half-planes of photonic crystal strong lateral confinement.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, - 37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, - 37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar
communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions.
The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz)
with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64
VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -
37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array
elements are feed using a direct feeding technique. This array antenna is suitable developed for use in
radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
ARRAY FACTOR IN CURVED MICROSTRIPLINE ARRAY ANTENNA FOR RADAR COMMUNICATION S...jantjournal
This paper presents the designed of varians array in curved microstripline antenna for radar communication. The antenna geometry comprises of three varians in matrics 2x2, 2x4 and 4x4 dimensions. The several array operates in C-Band frequencies (4GHz – 8GHz) and X-Band frequencies (8GHz-12GHz) with a 1.82 VSWR, -18.72dB Return loss, 0.29 reflection coefficient, and 5.8dB gain for 2x2 array, 1.64 VSWR, -16.17dB Return loss, 0.24 reflection coefficient, and 5.4dB gain for 2x4 array, 1.04 VSWR, -37.70dB Return loss, 0.19 reflection coefficient, and 7.6dB gain for 4x4 array. All of the varians in array elements are feed using a direct feeding technique. This array antenna is suitable developed for use in radar communication systems.
Diagnosis of Faulty Sensors in Antenna Array using Hybrid Differential Evolut...IJECEIAES
In this work, differential evolution based compressive sensing technique for detection of faulty sensors in linear arrays has been presented. This algorithm starts from taking the linear measurements of the power pattern generated by the array under test. The difference between the collected compressive measurements and measured healthy array field pattern is minimized using a hybrid differential evolution (DE). In the proposed method, the slow convergence of DE based compressed sensing technique is accelerated with the help of parallel coordinate decent algorithm (PCD). The combination of DE with PCD makes the minimization faster and precise. Simulation results validate the performance to detect faulty sensors from a small number of measurements.
Using Subspace Pursuit Algorithm to Improve Performance of the Distributed Co...Polytechnique Montreal
This paper applies a compressed algorithm to improve the spectrum sensing performance of cognitive radio technology.
At the fusion center, the recovery error in the analog to information converter (AIC) when reconstructing the
transmit signal from the received time-discrete signal causes degradation of the detection performance. Therefore, we
propose a subspace pursuit (SP) algorithm to reduce the recovery error and thereby enhance the detection performance.
In this study, we employ a wide-band, low SNR, distributed compressed sensing regime to analyze and evaluate the
proposed approach. Simulations are provided to demonstrate the performance of the proposed algorithm.
High Resolution Method using Patch Circular Array IJECEIAES
Smart antennas have recently received increasing for improving the performance of wireless radio systems. In this research article, we have used a patch antenna using uniform circular arrays (UCA) with central element for direction of arrival (DOA). A central element was added to arrays in order to increase steering capability of the proposed array. This geometry is used to determine the elevation and azimuth based on two famous algorithms of high resolution method: Matrix Pencil method (MP) and MUltiple Signal Classification (MUSIC).The comparison results demonstrate clearly that the matrix pencil is more accurate and stable to estimation of direction of arrival compared to the MUSIC algorithm.
Boosting CED Using Robust Orientation Estimationijma
n this paper, Coherence Enhancement Diffusion (CED) is boosted feeding external orientation using new
robust orientation estimation. In CED, proper scale selection is very important as the gradient vector at
that scale reflects the orientation of local ridge. For this purpose a new scheme is proposed in which pre
calculated orientation, by using local and integration scales. From the experiments it is found the proposed
scheme is working much better in noisy environment as compared to the traditional Coherence
Enhancement Diffusion
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
The paper addresses the importance of welding design to prevent corrosion at steel. Welding is
used to join pipe, profiles at bridges, spindle, and a lot more part of engineering construction. The
problems happened associated with welding are common issues in these fields, especially corrosion.
Corrosion can be reduced with many methods, they are painting, controlling humidity, and also good
welding design. In the research, it can be found that reducing residual stress on the welding can be
solved in corrosion rate reduction problem.
Preheating on 500oC and 600oC give better condition to reduce corosion rate than condition after
preheating 400oC. For all welding groove type, material with 500oC and 600oC preheating after 14 days
corrosion test is 0,5%-0,69% lost. Material with 400oC preheating after 14 days corrosion test is 0,57%-0,76%
lost.
Welding groove also influence corrosion rate. X and V type welding groove give better condition to reduce
corrosion rate than use 1/2V and 1/2 X welding groove. After 14 days corrosion test, the samples with
X welding groove type is 0,5%-0,57% lost. The samples with V welding groove after 14 days corrosion test is
0,51%-0,59% lost. The samples with 1/2V and 1/2X welding groove after 14 days corrosion test is 0,58%-
0,71% lost.
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
One of the major environmental concerns is the disposal of the waste materials and utilization of
industrial by products. Lime stone quarries will produce millions of tons waste dust powder every year. Having
considerable high degree of fineness in comparision to cement this material may be utilized as a partial
replacement to cement. For this purpose an experiment is conducted to investigate the possibility of using lime
stone powder in the production of SCC with combined use GGBS and how it affects the fresh and mechanical
properties of SCC. First SCC is made by replacing cement with GGBS in percentages like 10, 20, 30, 40, 50 and
by taking the optimum mix with GGBS lime stone powder is blended to mix in percentages like 5, 10, 15, 20 as
a partial replacement to cement. Test results shows that the SCC mix with combination of 30% GGBS and 15%
limestone powder gives maximum compressive strength and fresh properties are also in the limits prescribed by
the EFNARC.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Essentials of Automations: Optimizing FME Workflows with ParametersSafe Software
Are you looking to streamline your workflows and boost your projects’ efficiency? Do you find yourself searching for ways to add flexibility and control over your FME workflows? If so, you’re in the right place.
Join us for an insightful dive into the world of FME parameters, a critical element in optimizing workflow efficiency. This webinar marks the beginning of our three-part “Essentials of Automation” series. This first webinar is designed to equip you with the knowledge and skills to utilize parameters effectively: enhancing the flexibility, maintainability, and user control of your FME projects.
Here’s what you’ll gain:
- Essentials of FME Parameters: Understand the pivotal role of parameters, including Reader/Writer, Transformer, User, and FME Flow categories. Discover how they are the key to unlocking automation and optimization within your workflows.
- Practical Applications in FME Form: Delve into key user parameter types including choice, connections, and file URLs. Allow users to control how a workflow runs, making your workflows more reusable. Learn to import values and deliver the best user experience for your workflows while enhancing accuracy.
- Optimization Strategies in FME Flow: Explore the creation and strategic deployment of parameters in FME Flow, including the use of deployment and geometry parameters, to maximize workflow efficiency.
- Pro Tips for Success: Gain insights on parameterizing connections and leveraging new features like Conditional Visibility for clarity and simplicity.
We’ll wrap up with a glimpse into future webinars, followed by a Q&A session to address your specific questions surrounding this topic.
Don’t miss this opportunity to elevate your FME expertise and drive your projects to new heights of efficiency.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
To Graph or Not to Graph Knowledge Graph Architectures and LLMs
International Journal of Engineering Research and Development
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN: 2278-800X, www.ijerd.com
Volume 10, Issue 5 (May 2014), PP.41-48
41
Modelling and Surface Analysis of Deployable Mesh Reflector
Mithun Ekanathan1
, Sujithkumar N.2
, Dileeplal J.3
,
Y. S. Shankar Narayan4
1
P. G. Scholar, Mar Athanasius College of Engineering, Kothamangalam, Kerala, India
2, 4
Scientist/Engineer, ISRO Satellite Centre, Banglore, Karnataka, India
3
Associate Professor, Mar Athanasius College of Engineering, Kothamangalam, Kerala, India
Abstract:- Focal length of an antenna is a critical parameter when it comes to setting the feed or the receiver. In
this paper, a technique for least-squares fitting of the elliptic paraboloid in 3D data set is presented. The
objective is to estimate the invariants and the focal length of the deployable mesh reflector using the linear least-
squares based fitting mechanism. The 3D data set will be acquired from the flight model hardware using close
range photogrammetry (CRP) and the points will be used as input to the least square based fitting mechanism.
The technique also describes how to estimate the Euler angles and orientation of the antenna. Estimating the
variations of the focal length in each deployment tests will help in deciding the placement of the feed or the
receiver.
Keywords:- Parameter estimation, paraboloid, fitting mechanism, mesh reflector, focal length
I. INTRODUCTION
Future space based communication; remote sensing and space exploration missions will require large
antenna reflectors capable of communicating with ground systems. They are also needed for missions beyond
Earth‟s orbit where information must be transmitted over long distances. In order to support such large amounts
of data, at long distance an antenna that can receive and transmit a large amount of radiation must be employed.
If the distance between the mission and Earth grows to the order of astronomical units, there will be additional
burdens on the antenna to radiate enough power to compensate for a large loss of the signal over such a large
distance. The power that radiates from the antenna increases with the size of the reflector. Therefore, the need
for such large data transfer rates leads to the necessity for aperture antennas which have large parabolic
reflectors. Reflector antennas are particularly effective for the purpose of concentrating a signal over long
distances. Unfortunately, the limited volume of a launch vehicle or spacecraft places restriction on the size of a
rigid antenna reflector [2].
Since the late 1960‟s, deployable mesh reflectors have been favoured for their potential to fill large
apertures with extremely lightweight hardware. To allow larger reflectors to serve these missions, a deployable
antenna is desirable. Such an antenna has a reflector which is made of a light–weight material, can be collapsed
or folded for compact stowing and is deployable at an appropriate time.
Measure of performance of these parabolic reflectors is the stability of reflecting surface after
deployment on orbit. Reflecting surface is characterised by its invariants (major axis, minor axis, focal length)
by measurement of coordinates and estimation. Test will be repeated to show that these parameters do not
change in each deployment test on ground. In the following sections a methodology to estimate parameters of an
elliptical paraboloid reflecting surface is described.
II. PROBLEM DESCRIPTION
The antenna is a parabolic mesh reflector of 6m aperture diameter. It consists of a mesh reflector made
of gold plated molybdenum wire. The truss is made up of carbon fibre reinforced plastic (CFRP) and the vertical
tie support is made up of Kevlar. When the antenna is deployed, it is essential to achieve a parabolic surface
with a surface accuracy of less than 2mm. But due to error accumulations occurring in the manufacturing and
assembly process, designed parabolic surface will have some errors. Variation in the focal length of the reflector
will affect the location of the feed in the assembly. This study attempts to show that the invariants and errors are
stable in different trials of deployment tests and estimate the magnitude of the same.
A least square based fitting technique to recover the parameters of the surface from its 3D data, of co-
ordinates measured at the nodes, is discussed in the reminder of this paper. The antenna specification is shown
below:
Surface accuracy : < 2 mm
Antenna aperture size (d) : Ø 6000 mm
Focal length (f) : 4380 mm
2. Modelling and Surface Analysis of Deployable Mesh Reflector
42
f/d ratio : 0.73
Antenna type : Offset type (550mm offset)
The objectives of the methodology are as follows:
To estimate the unknown parameters of quadratic surface given by photogrammetric coordinates of
unfurlable antenna.
To prove that the obtained quadratic surface is an elliptical paraboloid.
To determine the invariants and focal length of the elliptical paraboloid.
III. METHODOLOGY
Surface recovery is commonly requisite in automatic object recognition and visual inspection,
particularly in surface model-based systems. In such procedures the surface recovery is typically a key
processing activity. Processing schema that enable recovery of a surface-based model from a 3D data typically
include tasks of local surface property estimation and reconstruction which involves finding the parameters of
the best fitting surface [6]. The least squares approach is a popular method in statistical estimation and its
application is found common in computer vision. In order to determine the focal length of the paraboloid, the
unknown parameter is to determined first, followed by estimation of the shape from the 3D data and then
reconstruction based on the estimated parameters. Reconstruction helps to determine the invariants in order to
find the focal length of the antenna.
A. Determining the unknown parameters
The Gauss-Markoff model is used to estimate the unknown parameters. The Gauss-Markoff model is
represented as follows:
Xβ = Y + e (1)
Where, „X‟ is an n x u matrix of given coefficients, „β‟ a u x 1 matrix of unknown fixed parameters and „Y‟ an n
x 1 random vector of observations. The matrix „e‟ represents the error matrix. The above equation is also known
as observation equation [5].
The polynomial model often serves the purpose to fit a planar curve or a surface in three-dimensional
space E3
to measured data. If for instance a curve is given in E2
, where a rectangular (x, y) coordinate system is
defined, and if on the curve points Pi with coordinates (xi, yi) are selected such that for given abscissae xi the
ordinates yi are measured, then the curve may be represented by the polynomial „β1 + xiβ2 + xi
2
β3 +…+ xi
u-1
βu-1
equal to E (yi) with i ε {1,2…,n}, where β1, β2,…, βu-1 denote the unknown parameters of the polynomial model.
The equation for a general quadric in Cartesian space is,
β1x2
+ β2y2
+ β3z2
+ β4xy + β5yz + β6xz + β7x + β8y + β9z + β10 = 0 (2)
It is possible to re-write Eq. (2) in a form with nine coefficients since only nine of its ten coefficients are
independent. For example, for the cases that β10 ≠ 0, Eq. (2) can be rewritten as
β1x2
+ β2y2
+ β3z2
+ β4xy + β5yz + β6xz + β7x + β8y + β9z = 1 (3)
Reconstructing a general quadric requires determining the nine independent coefficients βi (i = 1, 2, …, 9).
Next, is a description of how the nine quadric coefficients of Eq. (3) can be recovered using a linear least-
squares approach. It is assumed the least-squares fitting is performed on an input of m 3D points (xi, yi, zi). If
there are m sample points, there are m(x, y, z) values. Theoretically, the nine unknown parameters can be solved
from a group of nine linear equations of the form of Eq. (3), each of which has one data point (xi, yi, zi) assigned
to its corresponding variables x, y and z. In this way, the values of coefficients can be acquired with only nine
input sample points. However, due to sampling error, such results are not robust [8].
To enable robust fitting, an over-constrained system of m linear equations (i.e., m > 9) Eq. (1) is considered
where,
Xmxn = (4)
Eq. (4) is the coefficient matrix of the linear equation group and n = 9.
Additionally,
β = [β1 β2 β3 β4 β5 β6 β7 β8 β9]T
(5)
is the vector of unknown variables. The right-side term is
Ym×1 = [1 1 . . . 1]T
(6)
3. Modelling and Surface Analysis of Deployable Mesh Reflector
43
Normally, the least squares solution does not satisfy all equations in the group, but it minimizes the value of the
residual error. The least-squares solution „X‟ to this system of equations is the solution that minimizes the
residual error
e = ||Xβ – y||2 (7)
and this solution is optimal in the least-squares sense. The solution „β‟ can be computed using the normal
equation
β = (XT
X)-1
XT
Y (8)
If the sample data points are not concentrated at a single point, line or plane (which are the reduced dimension
cases), then the rows and columns in matrix X will not be linearly co-related, and therefore the matrix XT
X will
be non-singular. When XT
X is non-singular, there is guaranteed to exist a least-squares solution vector β [8].
Thus far, the coefficients of Eq. (3) have been determined. However, the coefficients of the equation do not have
clear geometric significance, such as the symmetric centre, if any, of the quadratic surface, its translation from
the origin, and the orientation of the surface. Therefore the next step is to estimate the surface type or shape.
B. Estimating the shape of the quadratic surface
Surface type can be determined using the surface‟s invariants Δ and D, which are invariant with respect
to translation and rotation [7]. For an arbitrary general quadric defined in the form of Eq. (2), the invariant Δ is
Δ = (9)
The invariant D is
D = (10)
The relationship between quadric surface type and the invariants is summarized in Table I.
Table I: Quadric surface classification via invariant values
D ≠ 0
Central quadric surface
D = 0
Non-central quadric surface
Δ > 0 Single-sheet hyperboloid Hyperbolic paraboloid
Δ < 0 Ellipsoid or dual-sheet
hyperboloid
Elliptical paraboloid
Δ = 0 Cone Cylinder or plane
Comparing the values of D and Δ with Table I will help in determining the shape of the quadratic
surface [7]. After determining the quadratic surface, the standard equation of the type of surface is considered
and the invariants are determined.
C. Paraboloid reconstruction
The standard equation of an elliptic paraboloid is
f(x,y,z) = + - z = 0 (11)
Eq. (11) is formed for the assumed parameter c = 1. In other words, a and b are the shape parameters of the
paraboloid, i.e., the half lengths of its cross-sectional ellipse at z=1.
According to principle axes theorem, the Eq. (2) can be written in matrix form as follows:
xT
Ax + Gx + H = 0 (12)
where, x = , A = , G = and H = . If the coefficients of cross-products are
zero then no rotation is necessary. Also if it‟s zero, then A is symmetric and also there exist an orthogonal
matrix R such that RT
AR is equal to a diagonal matrix. The matrix R must be orthogonal and its determinant
will be . This matrix can be thought of a sequence of three rotations, one about each principle axis, first about
x-axis, then the y-axis and finally z-axis [1]. The matrix will be of the form
R = R(θx)R(θy)R(θz) (13)
4. Modelling and Surface Analysis of Deployable Mesh Reflector
44
The standard equation of an elliptic paraboloid can be re-written in terms of matrices and vectors, to yield a
form similar to Eq. (12), as
xT
Ax + Gx = H (14)
where,
x = (15)
A = (16)
G = (17)
„H‟ is zero in Eq. (14). After certain translation and rotation Eq. (14) becomes
x`T
A1x` + G1x`= H1 (18)
where,
x` = (19)
A1 = RT
AR (20)
R = R(θx, θy, θz) = (21)
and, G1 = GT
R. R is a 3x3 standard orthogonal matrix representing a rotational transform, and θx, θy and θz are
three rotation angles that describe the quadratic‟s orientation with respect to the standard orientation. Since G1 is
the product of GT
and R, it is a vector denoted as follows:
G1 = (22)
Because matrix A1 is symmetric, there are only six independent elements in it. By expanding „x`T
Ax` = 0‟ and
comparing it to Eq. (2), the translation values x0, y0, z0 and the 6 independent elements of A1 can be computed.
The process is as follows.
If it is assumed that,
A1 = (23)
Then according to Eq. (19) and Eq. (23), x`T
A1x` = 0 can be written as:
(24)
After comparing Eq. (24) with Eq. (2), the coefficients of Eq. (2) can be represented as follows:
(25)
(26)
(27)
(28)
(29)
(30)
(31)
(32)
(33)
(34)
For paraboloids, the values „wi‟ in the Eq. (22) are non-zero; w1=r31, w2=r32, and w3=r33. Since w1, w2, and w3
are not zero, the values of x0, y0, z0 cannot be solved directly using the linear least-squares formulation. Since
these values cannot be found, the values which directly and indirectly depend on them also cannot be
determined. Specifically, the value for u and the elements of A1 cannot be found, which prevents determination
of the shape and orientation parameters. Therefore, the next step is to find the location, orientation, and shape
parameters for elliptic paraboloid. First, a variable v is introduced, where
v = 1/u (35)
and perform the orthogonal decomposition (diagonalization) on a matrix,
5. Modelling and Surface Analysis of Deployable Mesh Reflector
45
A2 = vA1 = (36)
The result must be,
A2 = RT
(vA1) R (37)
The R in Eq. (37) is same as the R in Eq. (21). Therefore the values of wi can be found from eigen-analysis of
Eq. (36). If Eqs. (25) – (30) and Eq. (35) are substituted in Eqs. (31) – (33), then,
(38)
(39)
(40)
Here x0, y0, z0 and v are unknown. The unknown translational variables x0, y0 and z0 can be represented by
expressions of v according to Eqs. (38) – (40),
(41)
(42)
(43)
After dividing both sides of Eq. (34) by u and then substituting Eqs. (25) – (30) and (41) – (43) into it, the result
is an expression of the form:
(44)
Where, q = 0 and, p and s are functions of the known coefficients , ,.., and r31, r32, r33. Furthermore, the
value s is:
(45)
Eq. (45) is exactly the invariant Δ for a general quadratic [7].
In addition the value of p is
(46)
Thus p is,
(47)
Since each of p and s can be expressed as a real multiple of the invariant Δ of a paraboloid surface, and since Δ
must be negative for elliptic paraboloids (Table I), s > 0 and p < 0; a real solution for v is ensured. Therefore, the
value of v can be found using
(48)
It is necessary to determine the sign of v. Because of Eq. (37), vA is a diagonal matrix. Furthermore, according
to the definition of matrix A in Eq. (16), its non-zero eigenvalues (diagonal entries) must be positive. Therefore,
the sign of v can be determined by finding A2‟s eigenvalues; if A2‟s eigenvalues are negative, then v must be
negative [1].
Once v has been determined, evaluation of Eqs. (16) and (37)–(40) allows determination of x0, y0, z0, a, and b.
Thus all of the location, orientation, and shape information can be extracted for elliptic paraboloid antenna.
D. Estimating the focal length
Now that the profile parameters „a‟ and „b‟ are known at an assumed value of „c‟ the focal length can directly be
calculated using the formula [7]:
6. Modelling and Surface Analysis of Deployable Mesh Reflector
46
IV. RESULT
Seven sets of three-dimensional data required for the analysis was obtained using photogrammetry and
the antenna was plotted using MatLab software. The methodology discussed in the previous section was applied
and the analysis was conducted using MatLab. The results are discussed as follows.
The diagram consists of all the coordinates of the mesh reflector as well as the coordinates of the truss. A total
of 163 coordinates constitutes the mesh reflector and 18 coordinates belong to the deployable truss. Since the
surface analysis was conducted only for the mesh reflector, the coordinates belonging to the truss was
eliminated and the meshed diagram of the reflector was plotted.
Fig. 1: Isometric view of the coordinates of the UFA
Fig. 2: Isometric view of the mesh reflector
A. Estimating unknown parameters
Eq. (3) is selected as the standard equation to estimate the unknown parameters. The coordinates of the
mesh reflector are known. Substituting the coordinates into Eq. (5) the coefficient matrix „X‟ is obtained. Matrix
„Y‟ is known as the unit vector matrix or the response matrix. Eq. (8) is solved to find the unknown parameters
and therefore the „β‟ matrix is obtained.
Since X, β and Y are now known matrices, Eq. (9) can now be solved to get the error plot.
7. Modelling and Surface Analysis of Deployable Mesh Reflector
47
Fig. 3: Error plot
B. Estimating the shape of the quadratic surface
The values of matrix β are now known. Substituting the values in Eq. (9) and Eq. (10) values of „Δ‟ and „D‟
were found to be,
Δ = -2.1874e-10
D = 7.8144e-15 ≈ 0
The value of Δ is a negative value and the value of D is approximately equal to zero. Hence, from Table I, it can
be concluded that the quadratic surface is an elliptic paraboloid.
C. Paraboloid reconstruction and focal length estimation
The invariants and focal length of all seven sets of data were found successfully, following the steps
explained in sub-section C of section III. The ellipse was cut at an assumed value c = 44. The result is shown in
Table II.
Table II: Final result
Deployment
Test No.
Major Minor c Focal Length Ellipticity
1 1960.5 1821.7 44 4380.23 1.076176
2 1962.0 1822.1 44 4379.822 1.076763
3 1961.9 1821.7 44 4377.067 1.076956
4 1962.2 1822.1 44 4379.346 1.076878
5 1961.8 1821.8 44 4377.7501 1.076859
6 1962.0 1821.9 44 4377.9034 1.076928
7 1961.9 1822.1 44 4379.929 1.076725
V. CONCLUSION
An indirect technique of least-squares fitting of the elliptic paraboloid mesh reflector in 3D data has
been presented. Using this approach the invariants and the focal length of the paraboloid reflector was estimated.
The result matches with the design parameters. This shows that the technique was helpful in recovering the
surface parameters. The limitation of this technique is that the inputs included must be from only one surface
type. If the inputs include points from more than one surface type, fitting accuracy can be impacted.
8. Modelling and Surface Analysis of Deployable Mesh Reflector
48
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