This paper aims to identify the CIE Standard General Sky models that best match measured sky luminance distribution data from Roorkee, India for three different seasons - summer solstice, winter solstice, and equinox. Daylight coefficients were used to simulate spatial illuminance distribution in a sample room for Indian sky data and five CIE clear sky models. Analysis showed that CIE Sky Type 15 best fits summer and equinox seasons, describing a "white-blue sky with a wide solar corona effect", while Type 11 best fits winter, describing a "white blue sky with a clear solar corona". Identifying appropriate CIE sky models for a location can improve accuracy in predicting seasonal daylight availability.
20120417 IMechE YMS Seminar on Daylighting modeling technique in built-enviro...ekwtsang
This document discusses daylight modeling techniques using global illumination programs like RADIANCE. It introduces key terms like daylight factor and glare index used to assess daylighting. It explains the RADIANCE system and common parameters used to control ambient bounces, divisions and accuracy. It also discusses two common misunderstandings - using a large single surface and applying luminance variation to a non-flattened surface. The document provides an overview of global illumination modeling and the RADIANCE software for daylighting studies.
Hottel's Clear Day Model for a typical arid city - Jeddahinventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
1) The document presents a method for short-term forecasting of surface solar irradiance at night using satellite imagery, allowing forecasts before sunrise.
2) It defines cloud classes based on brightness temperature differences in infrared satellite images at night, and derives a cloud index for each class by mapping infrared values to historical daytime cloud index values.
3) Validation using over 100 German weather stations over 6 months showed the nighttime cloud index can accurately forecast global horizontal irradiance in the hours before sunrise.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses methods for characterizing the global environment using satellite data to help overcome challenges posed by weather effects on missile defense sensors. It describes adjusting infrared imagery thresholds to approximate radar observations, extracting weather event boundaries, projecting 3D shapes onto a model Earth, and using an existing satellite constellation to provide continuous coverage. The goal is to determine visibility and sensor performance to optimize sensor selection and placement for missile defense.
The document discusses a solar resource lab where students learn to:
1. Forecast seasonal and daily solar insolation levels using clear-sky models and validate with measurements.
2. Estimate errors in their models by comparing to pyrheliometer and pyranometer readings.
3. Identify sources of error and derive optimal parameter estimates to improve their models.
This document describes an activity involving Hubble's law and the use of Cepheid variables as standard candles to measure distances to galaxies. It contains the following key points:
1) Cepheid variables have a direct relationship between their period and luminosity, allowing their distance to be estimated. Images show a Cepheid in galaxy M100 with an estimated period of [blank days].
2) Galaxies' recessional velocities can be measured via redshift and are plotted against distance. A linear relationship is found, described by Hubble's law as v=Hd, where H is the Hubble constant.
3) Estimating H from the graph gives a value of [blank] km/s/Mpc, consistent with current estimates
This document discusses integrating spheres, which are spherical devices that spatially integrate radiant flux from light sources for measurement purposes. Integrating spheres are commonly used to measure transmittance, reflectance, and radiant flux. They work by spatially averaging the light that enters the sphere so that measurements of radiance are not dependent on angle of incidence or collection. Key aspects discussed include the theory of radiation exchange within the sphere, considerations for designing spheres such as diameter, port size, coatings and baffles/diffusers, and different measurement applications like radiometry, photometry, and reflectance measurements.
20120417 IMechE YMS Seminar on Daylighting modeling technique in built-enviro...ekwtsang
This document discusses daylight modeling techniques using global illumination programs like RADIANCE. It introduces key terms like daylight factor and glare index used to assess daylighting. It explains the RADIANCE system and common parameters used to control ambient bounces, divisions and accuracy. It also discusses two common misunderstandings - using a large single surface and applying luminance variation to a non-flattened surface. The document provides an overview of global illumination modeling and the RADIANCE software for daylighting studies.
Hottel's Clear Day Model for a typical arid city - Jeddahinventionjournals
International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
1) The document presents a method for short-term forecasting of surface solar irradiance at night using satellite imagery, allowing forecasts before sunrise.
2) It defines cloud classes based on brightness temperature differences in infrared satellite images at night, and derives a cloud index for each class by mapping infrared values to historical daytime cloud index values.
3) Validation using over 100 German weather stations over 6 months showed the nighttime cloud index can accurately forecast global horizontal irradiance in the hours before sunrise.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
The document discusses methods for characterizing the global environment using satellite data to help overcome challenges posed by weather effects on missile defense sensors. It describes adjusting infrared imagery thresholds to approximate radar observations, extracting weather event boundaries, projecting 3D shapes onto a model Earth, and using an existing satellite constellation to provide continuous coverage. The goal is to determine visibility and sensor performance to optimize sensor selection and placement for missile defense.
The document discusses a solar resource lab where students learn to:
1. Forecast seasonal and daily solar insolation levels using clear-sky models and validate with measurements.
2. Estimate errors in their models by comparing to pyrheliometer and pyranometer readings.
3. Identify sources of error and derive optimal parameter estimates to improve their models.
This document describes an activity involving Hubble's law and the use of Cepheid variables as standard candles to measure distances to galaxies. It contains the following key points:
1) Cepheid variables have a direct relationship between their period and luminosity, allowing their distance to be estimated. Images show a Cepheid in galaxy M100 with an estimated period of [blank days].
2) Galaxies' recessional velocities can be measured via redshift and are plotted against distance. A linear relationship is found, described by Hubble's law as v=Hd, where H is the Hubble constant.
3) Estimating H from the graph gives a value of [blank] km/s/Mpc, consistent with current estimates
This document discusses integrating spheres, which are spherical devices that spatially integrate radiant flux from light sources for measurement purposes. Integrating spheres are commonly used to measure transmittance, reflectance, and radiant flux. They work by spatially averaging the light that enters the sphere so that measurements of radiance are not dependent on angle of incidence or collection. Key aspects discussed include the theory of radiation exchange within the sphere, considerations for designing spheres such as diameter, port size, coatings and baffles/diffusers, and different measurement applications like radiometry, photometry, and reflectance measurements.
This document summarizes a study that used radar imagery from the European Remote Sensing satellites ERS-1 and ERS-2 to map burnt forest areas in South Kalimantan, Indonesia following extensive fires in 1997. The researchers analyzed coherence images from 1996 and 1997 to identify areas that showed increased coherence after the fires, indicating vegetation clearing. They identified 552,000 hectares of burnt scars out of the 3.6 million hectare study area. Comparison to a multispectral SPOT image from September 1997 validated the radar analysis in delineating burnt areas. The study demonstrated the capability of radar interferometry to map fire-affected areas through changes in vegetation, providing an alternative to optical imagery during times of smoke and
This document summarizes the application of Marchenko imaging to a 2D ocean-bottom cable dataset from the North Sea Volve field. Marchenko redatuming estimates the full wavefield from virtual sources inside the medium using only surface reflection measurements and a smooth velocity model. The authors processed the field data to obtain an estimate of the reflection response required by Marchenko and used it to iteratively estimate focusing functions and retrieve up-going and down-going Green's functions. They performed target-oriented imaging at different depth levels using the redatumed reflection responses, revealing structures not visible in standard reverse-time migration. Marchenko imaging provides a way to obtain high-resolution images of target zones without needing detailed overburden models.
One day short course on Green Building Assessment Methods - Daylight Simulationekwtsang
This document provides an overview of different evaluation methods for daylighting design, including scale model measurement, simplified calculation methods like daylight factor and vertical daylight factor, and sophisticated computational methods like Maxwell's electromagnetic wave theory, radiosity, and ray tracing. It discusses components of the Radiance simulation system like sky description, material description, geometry description, and lighting description. It also covers standard CIE skies, daylighting requirements in LEED and BEAM Plus, and proposes using climate-based daylight modeling to provide long-term annual daylighting performance analysis.
Explanation of very simple methods for atmospheric corrections and an example adapted from a paper of the Dept. of Thermodynamics, University of Valencia, Spain.
Calculation of the Curvature Expected in Photographs of a Sphere's HorizonJames Smith
A formula is derived for the curvature of the horizon's image in photos of a sphere of radius R , taken by a camera with horizontal view angle alpha from height h above the sphere's surface. The formula is validated by means of an interactive GeoGebra construction: a key angle calculated from the formula derived here is compared to the angle actually present in the construction. Using the validated formula, the amount of curvature expected to be present in a photo of the Earth's horizon from an altitude of 3 m is calculated. The result is an order of magnitude smaller than typical degrees of barrel distortion present in consumers' digital cameras. Therefore, claims that "flat horizons in photos of waterscapes prove that the Earth is flat" are untenable.
This document discusses several approaches for atmospheric correction of remote sensing imagery:
1) Image-based methods like the dark pixel method and regression method estimate and remove atmospheric path radiance.
2) The empirical line method uses ground targets of known reflectance to model atmospheric effects.
3) Radiative transfer models precisely account for atmospheric conditions using numerical models like MODTRAN or 6S to convert pixel values to surface reflectance.
4) Relative correction methods normalize images without absolute calibration to surface reflectance. Atmospheric correction is needed to accurately analyze surface properties from remote sensing data and compare images acquired at different times or wavelengths.
This study compares the accuracy of daylighting simulations using Radiance and Lightscape software to on-site measurements of residential buildings in heavily obstructed areas of Hong Kong. The simulations overestimated daylight availability by up to 50% compared to measurements. A potential workaround method is suggested. The document outlines the on-site measurement process, calculation methods, computer simulation process, and concludes that both simulation programs overestimate daylight levels in conditions of high external obstruction.
The document describes the Phong shading model for modeling specular reflections. It explains that specular reflection results from total or near-total reflection of incident light in a concentrated region around the specular reflection angle. The Phong model sets the intensity of specular reflection proportional to the cosine of the viewing angle raised to a power 'n'. Higher values of 'n' produce shinier surfaces, while lower values produce duller surfaces. The model calculates specular reflection based on vectors representing the light source, viewer, and specular reflection direction.
This document provides an overview of cooling and heating load calculations and solar radiation modeling. It defines key terms related to solar geometry like latitude, declination, hour angles, and derived angles. It also describes the ASHRAE solar radiation model for calculating direct, diffuse and reflected radiation on surfaces. The objectives are to introduce cooling/heating load calculations, explain the importance of solar radiation, define relevant solar angles, and describe estimating radiation using ASHRAE models.
The Gauss Kruger projection is a generalized Transverse Mercator projection used to create coordinate systems for mapping countries. It defines parameters like the ellipsoid, latitude and longitude origins, false eastings and northings, and scale factor. These parameters are set differently for various countries that use the Gauss Kruger projection, such as Germany which uses 5 zones, Sweden, and Slovakia.
This document discusses Fourier domain optical coherence tomography (FD-OCT). It provides an overview of FD-OCT, including the Born approximation and measuring back scattered light. It describes how FD-OCT works by using a broadband light source and spectrometer to measure the interference of backscattered light. The document also discusses removing noise from FD-OCT images through phase shifting techniques.
This document provides an overview of the theoretical basis and methodology used in the METEONORM software. It discusses how hourly radiation values are referenced, and how meteorological data like radiation, temperature, wind, and rain are interpolated worldwide using inverse distance weighting models. Correction factors are also applied for different terrain features and locations near lakes, cities, valleys, and coastal areas. The interpolation process achieves a root mean square error of around 15 W/m2 for monthly global radiation averages and 1.9°C for monthly temperature averages.
The document describes a new algorithm for producing hemispherical snow water equivalent (SWE) products that assimilates weather station snow depth observations and spaceborne microwave data. The algorithm integrates snow clearance data and auxiliary forest coverage data to improve upon traditional methods. Over a 30-year time series, the assimilation of different data sources provides more accurate SWE estimates than interpolation alone, especially in areas with sparse weather station data. Validation shows the new product typically increases SWE accuracy compared to background kriging interpolation fields. The resulting 30-year SWE dataset for the Northern Hemisphere is available online.
The document describes photometric calibrations performed for the Dark Energy Survey (DES). It discusses:
1) The DES, which will use the Blanco telescope to image 5000 square degrees and use galaxy clusters, weak lensing, and other methods to study dark energy.
2) Calibration procedures including applying zeropoints and extinction corrections on a nightly basis and tweaking results between fields.
3) The author's work developing a program to calibrate standard star field magnitudes in DES filters using instrumental magnitudes, color terms, and iterative statistical analysis. Comparisons showed errors within 0.025 magnitudes.
The document discusses various illumination models used in computer graphics including ambient light, point light sources, distributed light sources, Beer Lambert's law, chromaticity diagrams, flat shading, Gouraud shading, the Phong illumination model, and the Ward illumination model. It provides details on how each model calculates light intensity and color values for surfaces and polygons in a 3D scene.
Determination of solar radiation - Heat transfer projectAmr Mousa
Heat transfer course project.
this project determines the solar radiation energy of the sun using basic tools such as arduino microcontrolller, temperature sensors and labview interface
You can find the project report in this link
https://drive.google.com/file/d/0B_lR1tM2uLiZZnB4WUphV2x0OXc/view?usp=sharing
This is our final project for the graduate course CSCI-580, 3D Graphics and Rendering, at University of Southern California. In this project we built a rendering library from scratch in VS-C++. We then used our library to render any 3D model, including the famous teapot. The library has many features. You can switch between Flat/Gouraud/Phong shading. Or switch the reflection/refraction on and off. It also has anti aliasing filter to enhance the quality of renders. Rotations and transformation could be easily done interactively. It was a tough project but we learned all the details of 3D graphic rendering, building one from scratch.
Atmospheric Correction of Remotely Sensed Images in Spatial and Transform DomainCSCJournals
Remotely sensed data is an effective source of information for monitoring changes in land use and land cover. However remotely sensed images are often degraded due to atmospheric effects or physical limitations. Atmospheric correction minimizes or removes the atmospheric influences that are added to the pure signal of target and to extract more accurate information. The atmospheric correction is often considered critical pre-processing step to achieve full spectral information from every pixel especially with hyperspectral and multispectral data. In this paper, multispectral atmospheric correction approaches that require no ancillary data are presented in spatial domain and transform domain. We propose atmospheric correction using linear regression model based on the wavelet transform and Fourier transform. They are tested on Landsat image consisting of 7 multispectral bands and their performance is evaluated using visual and statistical measures. The application of the atmospheric correction methods for vegetation analyses using Normalized Difference Vegetation Index is also presented in this paper.
This document describes three atmospheric correction algorithms for the Geostationary Ocean Color Imager (GOCI): the Standard NASA algorithm, the Spectral Shape Matching Method (SSMM), and the Sun-Glint Correction Algorithm (SGCA). It outlines the processing steps for each algorithm, including radiometric calibration, removal of Rayleigh and aerosol scattering, and derivation of remote sensing reflectance. Validation results show SSMM and SGCA provide reasonable matches to NASA standard processing of MODIS data, though all three GOCI algorithms could be improved by updating aerosol and ocean models. The document concludes the algorithms capture the essential ocean color measurement but would benefit from further refinement.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document reviews the importance and recent applications of polymer composites in orthopaedics. Polymer composites are increasingly being used as they can mimic natural bone properties like strength and stiffness. They have applications as bone plates, screws, cements, and intramedullary nails. Common polymers used include PEEK, PMMA, and UHMWPE. Polymer composites provide benefits over metal implants like lower stiffness similar to bone, biocompatibility, and resistance to corrosion. They are composites of a polymer matrix reinforced with fibers or particles to improve mechanical properties for load bearing applications.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document summarizes a research paper on designing a composite robotic controller using reduced order observer, output feedback, and LQR control methods.
[1] It develops an efficient method to linearize the dynamic model of a two-link robot manipulator around a linear trajectory using Lagrangian mechanics and LQR control. [2] The controller uses state feedback, output feedback, and a reduced order observer to estimate immeasurable states and make the system sensorless. [3] Computer simulations show the proposed controller provides good trajectory tracking and improved state estimation for the two-link manipulator.
This document summarizes a study that used radar imagery from the European Remote Sensing satellites ERS-1 and ERS-2 to map burnt forest areas in South Kalimantan, Indonesia following extensive fires in 1997. The researchers analyzed coherence images from 1996 and 1997 to identify areas that showed increased coherence after the fires, indicating vegetation clearing. They identified 552,000 hectares of burnt scars out of the 3.6 million hectare study area. Comparison to a multispectral SPOT image from September 1997 validated the radar analysis in delineating burnt areas. The study demonstrated the capability of radar interferometry to map fire-affected areas through changes in vegetation, providing an alternative to optical imagery during times of smoke and
This document summarizes the application of Marchenko imaging to a 2D ocean-bottom cable dataset from the North Sea Volve field. Marchenko redatuming estimates the full wavefield from virtual sources inside the medium using only surface reflection measurements and a smooth velocity model. The authors processed the field data to obtain an estimate of the reflection response required by Marchenko and used it to iteratively estimate focusing functions and retrieve up-going and down-going Green's functions. They performed target-oriented imaging at different depth levels using the redatumed reflection responses, revealing structures not visible in standard reverse-time migration. Marchenko imaging provides a way to obtain high-resolution images of target zones without needing detailed overburden models.
One day short course on Green Building Assessment Methods - Daylight Simulationekwtsang
This document provides an overview of different evaluation methods for daylighting design, including scale model measurement, simplified calculation methods like daylight factor and vertical daylight factor, and sophisticated computational methods like Maxwell's electromagnetic wave theory, radiosity, and ray tracing. It discusses components of the Radiance simulation system like sky description, material description, geometry description, and lighting description. It also covers standard CIE skies, daylighting requirements in LEED and BEAM Plus, and proposes using climate-based daylight modeling to provide long-term annual daylighting performance analysis.
Explanation of very simple methods for atmospheric corrections and an example adapted from a paper of the Dept. of Thermodynamics, University of Valencia, Spain.
Calculation of the Curvature Expected in Photographs of a Sphere's HorizonJames Smith
A formula is derived for the curvature of the horizon's image in photos of a sphere of radius R , taken by a camera with horizontal view angle alpha from height h above the sphere's surface. The formula is validated by means of an interactive GeoGebra construction: a key angle calculated from the formula derived here is compared to the angle actually present in the construction. Using the validated formula, the amount of curvature expected to be present in a photo of the Earth's horizon from an altitude of 3 m is calculated. The result is an order of magnitude smaller than typical degrees of barrel distortion present in consumers' digital cameras. Therefore, claims that "flat horizons in photos of waterscapes prove that the Earth is flat" are untenable.
This document discusses several approaches for atmospheric correction of remote sensing imagery:
1) Image-based methods like the dark pixel method and regression method estimate and remove atmospheric path radiance.
2) The empirical line method uses ground targets of known reflectance to model atmospheric effects.
3) Radiative transfer models precisely account for atmospheric conditions using numerical models like MODTRAN or 6S to convert pixel values to surface reflectance.
4) Relative correction methods normalize images without absolute calibration to surface reflectance. Atmospheric correction is needed to accurately analyze surface properties from remote sensing data and compare images acquired at different times or wavelengths.
This study compares the accuracy of daylighting simulations using Radiance and Lightscape software to on-site measurements of residential buildings in heavily obstructed areas of Hong Kong. The simulations overestimated daylight availability by up to 50% compared to measurements. A potential workaround method is suggested. The document outlines the on-site measurement process, calculation methods, computer simulation process, and concludes that both simulation programs overestimate daylight levels in conditions of high external obstruction.
The document describes the Phong shading model for modeling specular reflections. It explains that specular reflection results from total or near-total reflection of incident light in a concentrated region around the specular reflection angle. The Phong model sets the intensity of specular reflection proportional to the cosine of the viewing angle raised to a power 'n'. Higher values of 'n' produce shinier surfaces, while lower values produce duller surfaces. The model calculates specular reflection based on vectors representing the light source, viewer, and specular reflection direction.
This document provides an overview of cooling and heating load calculations and solar radiation modeling. It defines key terms related to solar geometry like latitude, declination, hour angles, and derived angles. It also describes the ASHRAE solar radiation model for calculating direct, diffuse and reflected radiation on surfaces. The objectives are to introduce cooling/heating load calculations, explain the importance of solar radiation, define relevant solar angles, and describe estimating radiation using ASHRAE models.
The Gauss Kruger projection is a generalized Transverse Mercator projection used to create coordinate systems for mapping countries. It defines parameters like the ellipsoid, latitude and longitude origins, false eastings and northings, and scale factor. These parameters are set differently for various countries that use the Gauss Kruger projection, such as Germany which uses 5 zones, Sweden, and Slovakia.
This document discusses Fourier domain optical coherence tomography (FD-OCT). It provides an overview of FD-OCT, including the Born approximation and measuring back scattered light. It describes how FD-OCT works by using a broadband light source and spectrometer to measure the interference of backscattered light. The document also discusses removing noise from FD-OCT images through phase shifting techniques.
This document provides an overview of the theoretical basis and methodology used in the METEONORM software. It discusses how hourly radiation values are referenced, and how meteorological data like radiation, temperature, wind, and rain are interpolated worldwide using inverse distance weighting models. Correction factors are also applied for different terrain features and locations near lakes, cities, valleys, and coastal areas. The interpolation process achieves a root mean square error of around 15 W/m2 for monthly global radiation averages and 1.9°C for monthly temperature averages.
The document describes a new algorithm for producing hemispherical snow water equivalent (SWE) products that assimilates weather station snow depth observations and spaceborne microwave data. The algorithm integrates snow clearance data and auxiliary forest coverage data to improve upon traditional methods. Over a 30-year time series, the assimilation of different data sources provides more accurate SWE estimates than interpolation alone, especially in areas with sparse weather station data. Validation shows the new product typically increases SWE accuracy compared to background kriging interpolation fields. The resulting 30-year SWE dataset for the Northern Hemisphere is available online.
The document describes photometric calibrations performed for the Dark Energy Survey (DES). It discusses:
1) The DES, which will use the Blanco telescope to image 5000 square degrees and use galaxy clusters, weak lensing, and other methods to study dark energy.
2) Calibration procedures including applying zeropoints and extinction corrections on a nightly basis and tweaking results between fields.
3) The author's work developing a program to calibrate standard star field magnitudes in DES filters using instrumental magnitudes, color terms, and iterative statistical analysis. Comparisons showed errors within 0.025 magnitudes.
The document discusses various illumination models used in computer graphics including ambient light, point light sources, distributed light sources, Beer Lambert's law, chromaticity diagrams, flat shading, Gouraud shading, the Phong illumination model, and the Ward illumination model. It provides details on how each model calculates light intensity and color values for surfaces and polygons in a 3D scene.
Determination of solar radiation - Heat transfer projectAmr Mousa
Heat transfer course project.
this project determines the solar radiation energy of the sun using basic tools such as arduino microcontrolller, temperature sensors and labview interface
You can find the project report in this link
https://drive.google.com/file/d/0B_lR1tM2uLiZZnB4WUphV2x0OXc/view?usp=sharing
This is our final project for the graduate course CSCI-580, 3D Graphics and Rendering, at University of Southern California. In this project we built a rendering library from scratch in VS-C++. We then used our library to render any 3D model, including the famous teapot. The library has many features. You can switch between Flat/Gouraud/Phong shading. Or switch the reflection/refraction on and off. It also has anti aliasing filter to enhance the quality of renders. Rotations and transformation could be easily done interactively. It was a tough project but we learned all the details of 3D graphic rendering, building one from scratch.
Atmospheric Correction of Remotely Sensed Images in Spatial and Transform DomainCSCJournals
Remotely sensed data is an effective source of information for monitoring changes in land use and land cover. However remotely sensed images are often degraded due to atmospheric effects or physical limitations. Atmospheric correction minimizes or removes the atmospheric influences that are added to the pure signal of target and to extract more accurate information. The atmospheric correction is often considered critical pre-processing step to achieve full spectral information from every pixel especially with hyperspectral and multispectral data. In this paper, multispectral atmospheric correction approaches that require no ancillary data are presented in spatial domain and transform domain. We propose atmospheric correction using linear regression model based on the wavelet transform and Fourier transform. They are tested on Landsat image consisting of 7 multispectral bands and their performance is evaluated using visual and statistical measures. The application of the atmospheric correction methods for vegetation analyses using Normalized Difference Vegetation Index is also presented in this paper.
This document describes three atmospheric correction algorithms for the Geostationary Ocean Color Imager (GOCI): the Standard NASA algorithm, the Spectral Shape Matching Method (SSMM), and the Sun-Glint Correction Algorithm (SGCA). It outlines the processing steps for each algorithm, including radiometric calibration, removal of Rayleigh and aerosol scattering, and derivation of remote sensing reflectance. Validation results show SSMM and SGCA provide reasonable matches to NASA standard processing of MODIS data, though all three GOCI algorithms could be improved by updating aerosol and ocean models. The document concludes the algorithms capture the essential ocean color measurement but would benefit from further refinement.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document reviews the importance and recent applications of polymer composites in orthopaedics. Polymer composites are increasingly being used as they can mimic natural bone properties like strength and stiffness. They have applications as bone plates, screws, cements, and intramedullary nails. Common polymers used include PEEK, PMMA, and UHMWPE. Polymer composites provide benefits over metal implants like lower stiffness similar to bone, biocompatibility, and resistance to corrosion. They are composites of a polymer matrix reinforced with fibers or particles to improve mechanical properties for load bearing applications.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document summarizes a research paper on designing a composite robotic controller using reduced order observer, output feedback, and LQR control methods.
[1] It develops an efficient method to linearize the dynamic model of a two-link robot manipulator around a linear trajectory using Lagrangian mechanics and LQR control. [2] The controller uses state feedback, output feedback, and a reduced order observer to estimate immeasurable states and make the system sensorless. [3] Computer simulations show the proposed controller provides good trajectory tracking and improved state estimation for the two-link manipulator.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document summarizes research on coupled fixed point theorems in ordered metric spaces. It presents definitions of mixed monotone mappings and coupled fixed points. It then proves a new coupled fixed point theorem (Theorem 8) for mappings satisfying a contractive condition using the concept of g-monotone mappings. The theorem establishes the existence of a coupled fixed point when the mappings satisfy inequality (1). Finally, it presents coupled coincidence and common fixed point results (Theorems 9) for mappings satisfying integral type contractions.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
The document presents a mathematical model to determine the fundamental frequency of vibration of a continuous beam with distributed mass. The model uses matrix iteration to analyze the beam as a multi-degree of freedom system with lumped masses at nodal points. A numerical example of a 3 degree of freedom beam is provided. The flexibility matrix and dynamic matrix are formulated. The fundamental frequency is determined by iterating the displacement vector using the dynamic matrix until convergence is reached. The model was found to determine the fundamental frequency with 27.4% better accuracy than a previous model.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document provides a tutorial on designing microwave amplifiers using CAD software. It discusses:
1) The key steps in microwave amplifier design including selecting an active device, biasing it, characterizing the device, analyzing stability, and implementing matching networks.
2) Methods for stability analysis including the Rollett K-factor test, source-load circle graphical analysis on the Smith Chart, and evaluating the reflection coefficients Γin and Γout.
3) How CAD tools like AWR's Microwave Office can be used to design microwave amplifiers by simulating the circuit and evaluating performance based on the device specifications and design parameters.
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
This document summarizes the design of an oxygen concentration electric potential detector. It discusses the working principle based on the difference in oxygen concentration across a zirconia solid electrolyte producing a potential. It describes the hardware design including an AT89T51 microcontroller, A/D and D/A converters, display, and temperature control circuits. It also outlines the software design with modules for data acquisition, processing, calculation, display, interrupts and temperature control. The goal is to improve measurement accuracy, stability and performance of domestic oxygen detectors.
Electrochemical Treatment of Acid Green V dye solution in a tubular flow reactorIJERD Editor
This document summarizes research on the electrochemical treatment of synthetic wastewater containing Acid Green V dye in a tubular flow reactor. Experiments were conducted at different current densities and effluent flow rates to determine the effect on chemical oxygen demand (COD) reduction and color removal. The percentage reduction in COD and color removal were found to be highest (up to 100%) at the lowest flow rate of 10 liters per hour and highest current density of 2.5 A/dm2, across initial dye concentrations of 1500 and 3000 mg/L. A flow rate of 30 liters per hour and current density of 1.5 A/dm2 provided lower power consumption while still achieving good COD and color reduction.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
We would send hard copy of Journal by speed post to the address of correspondence author after online publication of paper.
We will dispatched hard copy to the author within 7 days of date of publication
International Journal of Engineering Research and DevelopmentIJERD Editor
The document provides a survey of research on sensor association rules for mining behavioral patterns from wireless sensor network data. Sensor association rules aim to discover temporal relationships between sensor nodes by detecting correlated events. Various approaches are discussed, including techniques for distributed in-network mining, handling data streams, reducing redundancy, and applying association rules to applications like missing data estimation. Overall, the survey finds that sensor association rules are an effective knowledge discovery technique for wireless sensor networks.
nternational Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
An Experimental and Simulation of Daylighting in Atrium Building in the TropicsYotin Saartphan
1) An experimental and simulation study was conducted to evaluate daylighting in an atrium building model in tropical conditions. Physical experiments using a scale model measured daylight illuminance levels and distributions in the adjoining space.
2) Simulation software (BESIM) that uses ray tracing and radiosity methods was used to calculate interior daylight levels and compared to measurements. Good agreement between simulations and measurements was found, validating the simulation approach.
3) Both experiments and simulations showed that daylighting in the atrium building was generally sufficient for interior spaces throughout the day due to strong tropical sunlight and sky luminance. Illuminance levels were highest in southern areas due to sun position, and decayed exponentially further from the light well.
VISUAL MODEL BASED SINGLE IMAGE DEHAZING USING ARTIFICIAL BEE COLONY OPTIMIZA...ijistjournal
Images are often degraded by atmospheric haze , a phenomenon due to the particles in the air that scatter light. Haze induces a loss of contrast,its visual effect is blurring of distant objects. This paper presents a novel algorithm for improving the visibility of an image degraded by haze. The proposed method uses a cost function based on human visual model to estimate airlight map. It employs Artificial Bee Colony optimization (ABC) as the optimization technique for estimating air light map. Image is dehazed by removing the estimatedairlight from the degraded image. The performance of the algorithm is tested and compared with various other dehazing methods and the proposed algorithm dehazes the image effectively outperforming other methods.
VISUAL MODEL BASED SINGLE IMAGE DEHAZING USING ARTIFICIAL BEE COLONY OPTIMIZA...ijistjournal
Images are often degraded by atmospheric haze , a phenomenon due to the particles in the air that scatter light. Haze induces a loss of contrast,its visual effect is blurring of distant objects. This paper presents a novel algorithm for improving the visibility of an image degraded by haze. The proposed method uses a cost function based on human visual model to estimate airlight map. It employs Artificial Bee Colony optimization (ABC) as the optimization technique for estimating air light map. Image is dehazed by removing the estimatedairlight from the degraded image. The performance of the algorithm is tested and compared with various other dehazing methods and the proposed algorithm dehazes the image effectively outperforming other methods.
This document discusses the components of natural light that reach a point inside a building, including the sky component (SC), externally reflected component (ERC), and internally reflected component (IRC). It provides details on calculating each component and how they are used to determine the overall daylight factor (DF). The sky component depends on the window width and distance from the point. The ERC uses the sky component multiplied by 0.2. The IRC is half the sky component. The DF is the sum of the three components and represents the ratio of indoor to outdoor illuminance. Methods using a protractor are described to determine the initial sky component.
This document discusses the components of natural light that reach a point inside a building, including the sky component (SC), externally reflected component (ERC), and internally reflected component (IRC). It provides details on calculating each component and how they are used to determine the overall daylight factor (DF). The sky component depends on the window width and distance from the point. The ERC uses the sky component multiplied by 0.2. The IRC is half the sky component. The DF is the sum of the SC, ERC, and IRC and represents the natural light as a percentage of exterior light. Methods using a protractor are described to determine the initial sky component.
Advanced Approach for Slopes Measurement by Non - Contact Optical TechniqueIJERA Editor
This document describes an advanced non-contact optical technique for measuring slopes. It introduces a numerical computation method to acquire surface shapes using optical moiré reflection. The method uses coherent illumination and fine pitch gratings to project a reference grating onto a surface and observe interference fringes. The sensitivity and accuracy of this slope measurement method is high. Equations are derived that relate the measured slopes to the optical and geometric parameters of the system.
- Christian Baker analyzed Herschel PACS spectroscopy data of dwarf galaxy NGC 5195 to determine characteristics of its cold gas and dust using a PDR model.
- Key emission lines were detected including [C II], [N II], [O I]63, and [O I]145. [O III] was below the detection threshold.
- Ratios of emission lines to total infrared flux suggested a heating efficiency about an order of magnitude lower than NGC 5195's companion galaxy M51.
- Analysis of line ratios indicated gas densities of log(n/cm-3) between 2.0-3.0 and radiation intensities of logG0 between 2.5-3.3.
This document presents equations to compute the efficiency of a parabolic-trough solar collector using solar position coordinates. The equations account for factors like universal time, day, month, year, longitude, latitude, and heliocentric and geocentric coordinates to determine the sun's position. The collector efficiency considers the direct and reflected solar energy incident on its glass cover as well as thermal losses. The developed equations can predict collector performance using meteorological and radiative data for any location.
The document describes implementing Phong shading over polygonal surfaces using OpenGL. Key aspects include reading mesh files to obtain vertex and face data, calculating vertex normals, setting up a light source, and applying the Phong illumination model at each point. Phong shading is computationally expensive but produces higher quality results than Gouraud shading by interpolating normals. The implementation subdivides triangles recursively until the pixel level to apply Phong's equations. Results using pyramid and octahedron meshes demonstrated Phong shading generated superior images compared to Gouraud shading.
Automatic Classification Satellite images for weather Monitoringguest7782414
This document discusses a system for automatically classifying satellite images to monitor weather patterns and provide early warnings of adverse weather. It describes segmenting images, calculating centroids and distances between regions to identify cloud movement, and setting an alarm if clouds move in a way that indicates potential adverse weather. Algorithms are provided for displaying images, segmenting regions of interest, computing centroids and distances, matching images to estimate cloud models, determining cloud proximity above earth regions, and setting an alarm based on cloud movement patterns. The goal is to develop an early warning system by analyzing successive satellite images at hourly intervals and predicting future cloud patterns and weather.
The document discusses lighting simulation tools used in an architectural lighting course. It describes SketchUp, Ecotect, and Radiance software that students will learn. Ecotect is demonstrated for daylight factor analysis and shading studies. Limitations are noted regarding sky models and accounting for multiple reflections in Ecotect simulations.
Good daylighting and shading design in urban outdoors not only provides a comfortable luminous environment, but also delivers energy savings and
comfortable environments for surroundings, particularly in the hot arid climate. Yet, it can lead to a reduction in the daylight availability leading to visual
discomfort. According to the Illuminating Engineering Society of North America (IESNA, 2000, 2011), it is essential that daylight effects be considered in
any space where daylight is admitted, even if it is not exploited as a light source, in order to reduce the need for artificial lighting. Therefore, an analysis
of solar access and shading is necessary for to assure visual comfort underneath the shading tents. This paper attempts to investigate seven different
shading scenarios addressing the solar radiation access underneath, in compliance with ANSI/ASHRAE/IESNA Standard 90.1-2007 recommendations,
by employing DIVA, which is an integration of Radiance and DAYSIM with thermal load simulation using Energy Plus within [1].
Feature Extraction from the Satellite Image Gray Color and Knowledge Discove...IJMER
Satellite take images of the Earth in selected spectral bands that are in both the visible and
the infrared portions of the electromagnetic spectrum. Many Satellites provide three types of Satellite
Images. These Images are Visible Satellite Image, Infrared Satellite Image, and Water Vapor Satellite
Image. These images are important for different reasons, and, in some cases, all three are needed to
accurately interpret atmospheric conditions. These Satellite images contain different types of cloud. This
paper shows cloud feature extraction using Histogram. A table that shows cloud existence in different
image is created, called Association table in which Y represents cloud is exist and N represent not exist.
Association rule mining is applied to this table to make relations between different clouds and discover
the knowledge about cloud existence.
46 optimization paper id 0017 edit septianIAESIJEECS
This paper is a comparisation study between an experimental data and Matlab simulation of output PV characteristic affected by the orientation and the tilt angle of a photovoltaic solar module with inclined plane and by the dimension of the panel. The PV panel was rotated towards the east, south and west and positioned for the angles 0°, 30°, 45°, 60° and 90°. In this position, the values of current, voltage and power are measured. In the other side, using the mathematical model to calculate the solar radiation incident on an inclined surface as a function of the tilt angle was developed in MATLAB/SIMULINK model. The optimum angles were determined as positions in which maximum values of solar irradiation and maximum power were registered to characterize the P-V and V-I photovoltaic panel.
The document provides an analysis of the lighting design for two spaces (Study Area and Workshop/Multipurpose Room) in a community library located on Jalan TAR. For the Study Area, daylight factor calculations show the space achieves a 6.4% average daylight factor, exceeding the 3-6% target range and making it considered "very bright". For the Workshop/Multipurpose Room, limited exposure to daylight due to adjacent buildings means artificial lighting is needed to achieve the required illuminance levels. Lumen method calculations are provided to determine the number and placement of light fixtures needed in both spaces.
Compressive Light Field Photography using Overcomplete Dictionaries and Optim...Ankit Thiranh
In this paper, a design is proposed for a compressive light field camera which will allow to recover light fields with higher resolution from a single image. Also, various other useful applications for light field atoms are discussed, including 4D light field compression and denoising.
The document discusses solar radiation and presents a mathematical model for predicting global solar radiation on a horizontal surface. It describes how solar radiation reaches Earth from the sun and the amount of energy received. The model calculates hourly, daily, and monthly global radiation based on factors like Julian date, cloudiness, and sun position. Validation shows the model estimates daily radiation within 4.5% accuracy and monthly radiation within 0.34% compared to experimental data.
Building Science_02_Report_Integration ProjectWinnie Ang
The document provides details on the lighting design for an urban infill library project. It includes:
1) A site analysis showing sun path diagrams and how sunlight will affect different areas at different times of day. Louvered facades and overhangs are proposed to control sunlight.
2) Daylight factor calculations for a third floor young adult library and fourth floor reading room, finding the young adult area is "extremely bright" and reading room "dark".
3) Artificial lighting calculations using the lumen method to determine the number and layout of LED pendant and linear strip lights needed to meet illumination standards.
This document provides an overview and validation of Re.SunTM, a software tool for assessing solar resources worldwide using mesoscale weather modeling and coupling techniques. Re.SunTM runs the WRF mesoscale numerical weather model to generate meteorological data, then applies clear sky models incorporating aerosol and gas data to estimate solar radiation indices. It was validated against measurements from 9 complex sites, showing a mean bias of 0.64% and root mean square error of 4%. Statistics demonstrate Re.SunTM can estimate average annual global solar radiation to within 4.14% of measured for 80% of cases. The document concludes Re.SunTM is useful for solar applications requiring site-specific resource assessment.
Similar to Welcome to International Journal of Engineering Research and Development (IJERD) (20)
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
This document summarizes a study on reducing corrosion rates in steel through welding design. The researchers tested different welding groove designs (X, V, 1/2X, 1/2V) and preheating temperatures (400°C, 500°C, 600°C) on ferritic malleable iron samples. Testing found that X and V groove designs with 500°C and 600°C preheating had corrosion rates of 0.5-0.69% weight loss after 14 days, compared to 0.57-0.76% for 400°C preheating. Higher preheating reduced residual stresses which decreased corrosion. Residual stresses were 1.7 MPa for optimal X groove and 600°C
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
The document summarizes a study on the use of ground granulated blast furnace slag (GGBS) and limestone powder to replace cement in self-compacting concrete (SCC). Tests were conducted on SCC mixes with 0-50% replacement of cement with GGBS and 0-20% replacement with limestone powder. The results showed that replacing 30% of cement with GGBS and 15% with limestone powder produced SCC with the highest compressive strength of 46MPa, meeting fresh property requirements. The study concluded that this ternary blend of cement, GGBS and limestone powder can improve SCC properties while reducing costs.
Study of Macro level Properties of SCC using GGBS and Lime stone powder
Welcome to International Journal of Engineering Research and Development (IJERD)
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN : 2278-800X, www.ijerd.com
Volume 5, Issue 2 (December 2012), PP. 01-05
Comparative Study of summer, Winter and Quinox Sky
Type of India Using Daylight Coefficient Method and
Cie Standard General Sky Model
Sutapa Mukherjee, M.Tech.
Assistant Professor, Electrical Engineering Department
B. P. Poddar Institute of Management & Technology, Kolkata-700052. INDIA
Abstract:- Energy efficiency provided by daylight requires an accurate estimation of the amount of daylight
entering a building. The actual daylight illuminance of a room is mainly influenced by the luminance levels and
patterns of the sky in the direction of view of the window at that time. The daylight coefficient concept, which
considers the changes in the luminance of the sky elements, offers a more effective way of computing indoor
daylight illuminances. Recently, Kittler et al. have proposed a new range of 15 standard sky luminance
distributions including the CIE (International Commission onIllumination) standard clear sky. Lately, these 15 sky
luminance models have been adopted as the CIE Standard General Skies.This paper aims to find out representative
CIE (International Commission on Illumination) Standard Clear Sky model(s) for three different seasons-winter
solstice, equinox, and summer solstice applicable for prevailing clear sky climatic conditions in India [Roorkee].
Indian measured sky luminance distribution database is available only for Roorkee[29051'N; 77053'E]. To find out
the best match between Indian measured sky luminance distribution and each of five CIE Standard Clear sky
models, only sky component of spatial illuminance distribution over the working plane of a room was simulated
by MATLABfor three different seasons. Daylight Coefficient method has been applied for the simulation using
Indian sky luminance database.The simulation has been done for the room with eight different window
orientations ranging from 00 to 3150 with an interval of 450 to generate data for the entire sky vault. To find out the
best fit CIE model(s)Indian measured sky luminance distribution data is taken as reference. Analysis revealed that
CIE Standard General Clear sky type 15 described as “White-blue sky, turbid with a wide solar corona effect”is
the best-fit clear sky model for both summer and equinox seasonsand sky type 11 described as “White blue sky
with a clear solar corona” is the best-fit clear sky model for winter seasonat Roorkee.
Keywords:- Daylight Coefficient method, CIE Standard general sky models, Daylight factor.
I. INTRODUCTION
Daylighting is an important issue in modern architecture.The evaluation of visual comfort and energy efficiency
due to daylighting requires an accurate estimation of the amount of daylight for any pointwithin the internal
space.Conventionally, the illuminance from natural sources is often determined in terms of daylight factor (DF) with the
calculations being based on an overcast sky [1], which is often considered to provide the worst design condition for
daylighting. Actually it has been found, from simultaneous measurements of daylight that the ratio of internal to external
illuminance varies greatly under real skies. This means that it is inaccurate to predict the illuminance at a point in a room by
just multiplying the level of external available daylight by the daylight factor or by any other constant ratio.Prediction of
daylight availability in an interior space at different seasons throughout a year is important for daylighting design.This
prediction of daylight availability is made either in absolute illuminance or in relative illuminance with respect to external
illuminance. In either case sky luminance distribution model or data is required. CIE(International Commission on
Illumination) proposed its homogeneous sky types with the understanding that the 15 sky luminance distributions represent
the sky type at any location all over the world for different seasons. Out of 15 sky types, five types represent overcast skies,
five types represent intermediate skies and the rest five types represent clear skies[2]. Attempts have been made earlier to
utilize CIE 15 General Sky models for daylight predictions [3] and also to correlate these Standard models with measured
sky luminance data [4]. So to utilize the CIE Standard general sky model for the prediction of daylight illuminance at a
particular location, the relevant sky type representing the prevailing sky luminance distribution for different seasons
throughout the yearmust be known.At present, Daylight Coefficient technique is the commonly used tool for daylighting
design using sky luminance distribution [5,6]. Under IDMP(International Daylight Measurement Program) monthly
averagedhourly sky luminance distribution data was available in India at Roorkee(latitude 290 51' (N), longitude(E) 77053' )
at three different seasonal conditions-summer solstice,winter solstice and equinox[7].
In this paper attempt was made to find out the best fit CIE Standard General Sky type(s) which represents sky
pattern at Roorkeeduring above three different seasonal conditions.The performance of the Indian sky model was also
evaluated along with CIE Standard skies. To do this one sample room with single-sided window was considered for
prediction of available daylight distribution on working plane and subsequent comparison. Two MATLAB programs were
written to compute absolute illuminance in Lux at different station points over working plane. In one program, measured
clear sky luminance data was takenusingDaylight Coefficient method and in the other program five types of CIE clear sky
models were used. The predicted data obtained from Daylight Coefficient method were taken as reference and percent
illuminance deviation were computed for each clear sky type to find outbest fitCIE sky type prevailing at Roorkee.
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2. Comparative Study of summer, Winter and Quinox Sky Type of India Using…
II. CIE STANDARD GENERAL SKY MODELS
In 2003 CIE published spatial luminance distribution data for fifteen CIE Standard General Skies. The relative sky
luminance distribution was modeled based on the theory of sunlight scattering within the atmosphere and expressed by the
product of two different exponential functions viz, gradation function ( ) and indicatrix function f(χ) as [2]
2
L f ( )* ( )
2 (1)
Lz f ( )* (0)
s
2
Lγα = Luminance (cd/m2) of any sky element specified by altitude angle γ and azimuth angle α
Lz = Luminance (cd/m2) of sky at zenith, i.e. at γ = π/2
χ = scattering angle between the sun and sky element
γs = altitude angle of sun
Here γ and α angles are in radian.
The direction of altitude angle is measured from horizon (0 0) upward up to zenith (900) and the direction of azimuth angle is
taken due north (00) and clockwise.
Now the gradation function is given by,
b
( ) 1 a *exp( )(2)
2
Cos( )
2
For zenith γ = π/2, and gradation function becomes
(0) 1 a *exp(b)(3)
The indicatrix function is given by,
f ( ) 1 c *[exp(d * ) exp(d * )] e * Cos 2 (4)
2
The scattering angle (χ) can be calculated from the following formula
Cos 1[Sin * Sin s Cos * Cos s * Cos( s )] (5)
where αs = solar azimuth angle (radian).
The indicatrix function for zenith
f ( s ) 1 c *[exp(d *( s ) exp(d * )] e * Cos 2 ( s ) (6)
2 2 2 2
wherea,b,c,d,e are standard parameters used to represent CIE 15 Standard General skies. The values of these
parameters are tabulated in Table 1.
2.1 Indian Measured Sky Luminance Distribution Data:
The sky luminance distributions of sunny clear sky condition during three seasons (summer solstice, winter
solstice and equinox) which were measured at Central Building research Institute [CBRI] with a sky-scanner from M/S EKO
Japan, having a field of view of 110 and the total measurements were completed for the whole sky vault in three minutes [7]
III. COMPUTATION OF SPATIAL ILLUMINATION DISTRIBUTION
The spatial illuminance distribution has been computed on 150 station points over working plane of a room having
dimension 30m x 20m x 4m with a centrally placed single-sided clear window opening of 28m long and 3m height. The
working plane has been considered at height of 1m from the floor. The reflectances of ceiling, walls and floor are taken as
80%, 70% and 20%.
The sky illuminance [E] at any horizontal station point is computed by
2 2
E L *Sin *Cos *d *d (7)
1 1
where α1, α2 and γ1, γ2 represent lower and upper limits of horizontal and vertical acceptance angles with respect to station
point.
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3. Comparative Study of summer, Winter and Quinox Sky Type of India Using…
3.1 With five CIE Standard clear skies:
Spatial illuminance distribution over the working plane was computed for five CIE Standard Clear Skies using
Eqn.(7) by including the values of Lγα from Eqn.(1). Now for clear sky condition Lγα depends on sun position specified by
solar altitude [γs] and solar azimuth [αs]. To compute sun position during winter, equinox and summer, three months viz.
January, March and June were considered respectively. The values of Julian day were taken as 15, 74 and 166 for the above
three months respectively. The computation was done for eight window orientations as mentioned earlier through developed
MATLAB program for three seasonal sky conditions. For computation of sun position and related parameters, algorithms
were taken from Daylight Algorithms [10]. The values of Zenith Luminance(Lz) at 12 noon is taken from measured sky
luminance data as given in Table 2.
Table - 1: Values of Standard parameters for five CIE Standard Clear Sky types [2,4]
For gradation For indicatrix
No. Type of CIE Standard Clear sky
a b c d e
11 White blue sky with a clear solar corona -1 -0.55 10 -3 0.45
12 Very clear/unturbid with a clear solar corona -1 -0.32 10 -3 0.45
13 Cloudless polluted with a broader solar corona -1 -0.32 16 -3 0.3
14 Cloudless turbid with a broader solar corona -1 -0.15 16 -3 0.3
15 White-blue sky, turbid with a wide solar corona effect -1 -0.15 24 -2.8 0.15
Table - 2: Values of Zenith Luminance at Roorkee at12 noon [7]
Season Value of Lz in kcd/m2
Summer 25.5
Equinox 5.8
Winter 4.1
3.2 With Indian Measured sky luminance data:
As there is no analytical expression for Indian sky luminance distribution Eqn.(7) can not be used directly. Here
Daylight Coefficient method was applied to use discrete sky luminance data available from measured iso-luminance contour
3.2.1 Daylight Coefficient Method:
Daylight illuminances inside a room are not in general proportional to the external illuminance, but depend on the
exact sky luminance distribution at that time. This is because a point in a room will receive direct light only from certain
areas of the sky and the illuminance within a room is not equally sensitive to changes in the luminance of different parts of
the sky.Daylight Coefficient method [10] utilizes the sky luminance data of the portion of the sky as seen from the station
point through the window to predict point-specific indoor illuminance. The Daylight Coefficient [ΔDγα] is defined by the
ratio of total illuminance at a particular point to the product of luminance of that sky element and the solid angle subtended
by sky element at that point.and mathematically expressed
𝛥𝐸 𝛾𝛼
𝐷 𝛾𝛼 = …………(8)
𝐿 𝛾𝛼 ∗𝛥𝑆 𝛾𝛼
where,
ΔEγα= illuminance at any station point for the sky element specified by angles γ,α
Lγα = luminance of that sky element
ΔSγα = solid angle subtended by above sky element at the station point.
To compute point-specific horizontal illuminance on working plane of a room the expression for Daylight
Coefficient is
𝐷 𝛾𝛼 = 𝑠𝑖𝑛γ…………..(9)
Hence the Eqn.(7) is modified as
𝛼 𝛾
𝐸 = 𝛼 2 𝛾2 𝛥𝐿 𝛾𝛼 ∗ 𝑆𝑖𝑛γ ∗ Cosγ ∗ Δγ ∗ Δα……..(10)
1 1
IV. ROOT MEAN SQUARE DEVIATION COMPUTATION
To find out the similarity between two sets of spatial illuminance distribution over the working plane, Root Mean
Square of percentilluminance deviation value was calculated. Theilluminance distribution obtained from Daylight
Coefficient method was taken as Referencevaluewhereas that obtained from five types of CIE General Standard Clear skies
andIndian Clear Design sky were taken as Test value.The minimum RMS value ofilluminance deviation was taken as an
indicator for the closest matching.
4.1 Results and conclusion:
It is important to mention here that available Indian measured sky luminance data [6] are hour-wise monthly
averaged data. Sky Luminance distribution data measured in January,March and June represent winter solstice, equinox and
summer solstice respectively.Moreover, linear interpolation was done to pick up sky luminance values for 145 skyelements
from iso-luminance contours which is one of the sources of deviation. On the other hand, the CIE sky models are
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4. Comparative Study of summer, Winter and Quinox Sky Type of India Using…
mathematical models with which day and time specific skyluminance distribution can be simulated. The Indian Design Clear
sky model assumes axiallysymmetric sky luminance distribution which is far from the real sky distribution.The computed
RMS values of percentilluminance deviation for eight window orientations and for three seasonswere tabulated in Table 4.
The average values ofpercent RMS deviations for the three seasons were graphically shown in Fig.1
Table - 4:RMS values of percentIlluminance deviations for Local solar time 12noon
Wnom(Deg) 0 45 90 135 180 225 270 315 Average % RMS Deviation
Window Orientation N NE E SE S SW W NW
Sky Type Percent RMS deviation for Summer Solstice
CIE_11 78 60 44 33 40 59 76 83 59
CIE_12 100 80 60 44 53 76 97 105 77
CIE_13 57 40 29 25 29 43 58 63 43
CIE_14 74 55 38 27 35 56 75 81 55
CIE_15 52 34 26 25 28 41 56 60 40
Sky Type Percent RMS deviation for Equinox
CIE_11 46 33 27 31 32 29 30 38 33
CIE_12 66 48 28 24 27 26 27 55 39
CIE_13 29 23 26 32 32 28 26 27 28
CIE_14 46 33 22 24 27 26 30 40 31
CIE_15 17 22 28 31 30 27 24 22 25
Sky Type Percent RMS deviation for Winter Solstice
CIE_11 57 43 26 27 29 26 27 40 34
CIE_12 83 64 33 23 27 24 32 59 43
CIE_13 47 35 22 27 34 31 25 34 32
CIE_14 72 55 30 31 42 38 33 53 44
CIE_15 21 18 17 33 47 42 26 21 28
80
Avg Percent Rms Deviation
Summer
60 solstice
Equinox
40
20 Winter
0
CIE_11 CIE_12 CIE_13 CIE_14 CIE_15
CIE Types
Fig.1Average of percent RMS deviation for three seasons
It is important to mention here that available Indian measured sky luminance data [6] are hour-wise monthly
averaged data. Sky Luminance distribution data measured in January, March and June represent winter solstice, equinox and
summer solstice respectively.
This study may be done by comparing iso-luminance contours of measured sky luminance distribution and CIE
mathematical models or by comparing sky luminance values of 145 sky elements. In this approach entire sky vault would be
taken into account. But in our approach sky illuminance distribution on working plane of a room was considered for
comparison because for the prediction of indoor illuminance the contribution from the visible portion of sky is much more
effective than the entire sky vault. The contributions from the entire sky come through reflection from external obstructions
and ground. In this study window height 3m was taken to include the effect of sky portions from horizon to well above
horizon about 700.
However, this comparison was done based on the daylighting distribution only for local time 12 noon when solar
azimuth is 1800. Similar hour-wise study for complete duration of day will be effective to draw more comprehensive
conclusion.
ACKNOWLEDGEMENT:
The authors wish to acknowledge the support received from Dr.R.Kittler and Dr.Danny H.W. Li through sending
their publications which we found useful to complete this report.
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5. Comparative Study of summer, Winter and Quinox Sky Type of India Using…
We also like to thank Indian Society of Lighting Engineers [ISLE] and specially to Mr.P.K.Bandyopadhyay, Past
President, ISLE for providing us a copy of the Report [Reference 7] published by Central Building Research Institute
[CBRI] containing Indian Measured Daylight Database.
REFERENCES
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Standard General Sky, Lighting Research & Technology, 38,2 (2006)
[3]. Danny H.W.Li, Daylight and energy implications for CIE standard skies, Energy Conversion and Management, 48
(2007)
[4]. Danny H.W. Li, Chris C.S. Lau, Joseph C. Lam, A study of 15 sky luminance patterns against Hong Kong
Data,Architectural Science Review,46,1 (2003)
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[6]. Danny H.W. Li, Gary H.W. Cheung, Chris C.S.Lau, A simplified procedure for determining indoor daylight
illuminance using daylight coefficient concept, Building and Environment 41, (2006)
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[8]. Guide for daylighting of buildings (2nd Revision), IS [Indian standard]:2440,(1975)
[9]. V Narashiman, B K Saxena, Measurement of Luminance distribution of clear blue sky in India, Indian J. Pure and
Applied Physics, 5, (1967)
[10]. Daylight Algorithms, Published by School of Architectural Studies, University of Sheffield, (1993)
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