106 research outputs found
Natural image matting with non-negative matrix factorization
No full textThis report summaries the work done by the author on his Final Year Project at
Nanyang Technological University (NTU) under Associate Professor Deepu Rajan.
The author was involved in implementing an effective way to realize image matting
using Non – Negative Matrix Factorization.
The report provides an overview of the project. It aims to provide the reader an
insight into the author’s role in the development of the matting algorithm. The report
explains the salient features of matting, Non-Negative Matrix Factorization and how
the entire development process was done. The report summarizes the results found
and compares the obtained results with other known algorithms with the use of
images.
It also highlights the domain knowledge, skills gained to accomplish these tasks and
the challenges faced in the process and how they were overcome. The technical
knowledge gained at NTU, was utilized in various ways to fulfill the requirements of
the project.Bachelor of Engineering (Computer Engineering
Microtron Irradiation Induced Tuning of Band Gap and Photoresponse of Al-ZnO Thin Films Synthesized by mSILAR
No full textAl-doped polycrystalline nano ZnO (Al-ZnO) thin films with different doping concentrations were successfully prepared by the microwave-assisted successive ionic layer adsorption and reaction (mSILAR) technique. The structural analysis along with the orientation of the prepared films was examined by powder x-ray diffraction (PXRD) patterns. The deposited film is polycrystalline and the (002) orientation enhanced upon doping. Additional investigations were carried out to study the effect of electron beam irradiation (e−-irradiation) on the band gap and photoconductivity of both irradiated and unirradiated samples. Both the Al doping and e−-irradiation led to the enhancement of the photoconductivity of prepared materials. This property enables us to tune the properties of materials for various applications by controlling dopant concentrations and e−-irradiation. The dependence of photocurrent on e−-irradiation of Al-ZnO thin films was not reported previously. Therefore, Al-doped polycrystalline nano-ZnO thin film is a promising material for band gap engineering and for the development of solar cells
Influence of metal nanoparticles on the light emission properties of rare-earth ions
No full textThe optical properties of metal nanoparticles (MNPs) can differ significantly from those of bulk material. Light can excite a collective oscillation of conduction electrons inside an MNP, thus creating a particle plasmon polariton in the MNP. At the resonance frequencies of the particle plasmon polaritons, the MNP absorbs and scatters light strongly, and the local field near the surface of the MNP changes more drastically as compared to other frequencies. When an oscillating electric or magnetic dipole emitter is placed in the vicinity of the nanoparticle, which acts as an optical nanoantenna, the radiative and non-radiative decay rates of the emitter can be modified due to the coupling between the particle plasmon of the MNP and the dipole emitter. The main focus of this thesis work is to study and understand the modification of the excitation and emission rates of the dipole emitters due to the changes in the local fields in the emitter’s surroundings introduced by metal nanoparticles with various shapes and sizes. The particle plasmon polariton properties of a metal nanoparticle can be utilized for the luminescence rate enhancement of the trivalent rare-earth ions, which can be incorporated into Si solar cells for the enhancement of their overall light-to-current conversion efficiency. At the beginning of this thesis work, the spatial consequences of various metal nanoparticles on radiative (γR) and non-radiative (γNR) decay rates of electric dipole (ED) and magnetic dipole (MD) emitters are investigated. For example, in the extreme nearfield region (d ≤10 nm) of a silver nanosphere, γNR of the ED and MD is observed to vary with 1/d3 and 1/d, respectively, where d is the distance between the dipole emitter and the surface of the silver nanosphere. Numerical results presented in this thesis show that the electric dipole transitions are quenched more strongly than the magnetic dipole transitions at extremely short distances from a metal nanoparticle surface. Furthermore, it is learned from the presented simulation results that when the dipole emitters can couple to a metallic nanoparticle with both electric and magnetic resonances, the electric dipole transitions are still quenched more than the magnetic dipole transitions at extremely close distance to the nanoparticle surface. In the next step, the effects of various MNPs on the photoluminescence emission rate of Sm3+ ions are studied by investigating the effects of the metal nanoparticles with various shapes and sizes on both the excitation and emission decay rates of the Sm3+ ion. The presented calculation results using the finite-element method show that it is more efficient to use nanoparticles made of aluminum than a noble metal for the implementation of rare-earth ions like Sm3+ (doped in a photoluminescence layer) in devices such as photovoltaic solar cells. The physical dimensions such as shape and size of the aluminum nanoparticle can be further modified to obtain an even more suiting aluminum nanoparticle for an experimentally feasible sample configuration with Sm3+ ions. Finally, the influence of gold nanoparticles of various shapes and sizes on the upconversion luminescence emission rate of Er3+ ions are presented and discussed. The presented results in this thesis work are the outcome of various numerical methods. The overall upconversion luminescence enhancement due to a large gold nanosphere (diameters = 300 nm) is compared quantitatively with the results from literature for smaller gold nanospheres (diameters: 100 nm, 140nm and 200 nm). A maximum overall enhancement of around 5% in the volume averaged upconversion luminescence is observed for the largest gold nanosphere with diameter 300 nm. There are almost no enhancements in the volume averaged upconversion luminescence observed for the smaller gold nanospheres discussed in this thesis work. In comparison to the maximum of only 5% in the volume averaged upconversion luminescence enhancement due to the large gold nanosphere, a maximum of around 33% is observed due to the gold nanodisk with length 300nm and height 25 nm. From the presented analysis, it is observed that a metal nanoparticle with large scattering efficiency at both the excitation and emission frequencies of the Er3+ion seems to be the most suitable for the enhancement of the upconversion luminescence rate. Furthermore, it is also observed that it is even more important for a metal nanoparticle to have a large scattering efficiency at the absorption frequency than at the emission frequency of the Er3+ ion in order to achieve a large upconversion luminescence rate enhancement
Distinguishing amateur and professional photographs
No full textPhotography is the art of capturing and handling images. There are many ways to define the aesthetics in photography. The act of quantifying these aesthetic properties directly to distinguish photographs taken by amateur and professional photographers is almost impossible. This is because there is no general consensus. As such, it is beneficial to develop an algorithm that can differentiate the photographs.
In today’s technological advanced society, there are several researches done by computer scientist and engineers specialised in the field of image processing to learn aesthetic properties of the photographs. The properties are changed into computable image features for classification of photographs.
The project requires the author to understand and implement one of the research papers. The author furthers his reach by deriving new features he discovered upon learning more about photography. This allowed him to improve on the classification accuracy.
In this report, the author explains the various aesthetic appeals of photographs that are used for photograph classifications. The concept of computer vision and image processing to use to extract these aesthetic properties in order to convert into computable data and the concept of machine learning to train a model which is used to differentiate photographs are studied in order to fulfil this project’s requirement.
To determine the feasibility of the improved design, an application is implemented on MATLAB platform. It automatically takes in thousands of already classified photographs taken by professional and amateur photographer as training datasets and another set of randomly chosen picture as testing datasets. The program, once executed, allows the author to differentiate the photographs. The main features, design methodology and test specification of the application are discussed in this report.
Performances analysis of the implemented application is noted. The author also identified further areas that can be enhanced.Bachelor of Engineering (Computer Engineering
Studies on Evaluation of Suitability of Mango Varieties Sindura, Mallika and Totapuri for Processing into Canned Products and Development of Blended Ready to Serve Beverages
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Formulation and Evaluation of Buccal Patches of Promethazine Hydrochloride
No full textMotion sickness is a condition in which there exists a disagreement between visually perceived movement and the vestibular system's sense of movement. Promethazine hydrochloride is the most suitable drug because of its anti-cholinergic effect and reduces the
nausea experienced during motion sickness. Because of the low systemic bioavailability and requirement of rapid onset of action for patients with nausea and motion sickness, buccal mucoadhesive administration dosage form is effective and safe, and unpleasant taste and local anaesthetic effect on tongue can be avoided. This dosage form is convenient for patients those who want any-time dosage especially when travelling. In the present work successful attempt was made to formulate buccal patches using 10 mg drug loaded in HPMC K4M and HPMC15cps with different plasticizers glycerine, PEG 400 and Propylene glycol in different compositions. The objectives for the proposed work are given in chapter III. Extensive literature survey was done before the experimental works for collection of theoretical and technical data. The review of literature is presented in chapter II. The materials and equipments used throughout the work are listed in chapter IV followed by Drug profile and excipient profiles. Methodology for the preparation and characteristic evaluations are included in chapter IV. Drug- excipient compatability was assessed by FTIR spectroscopy. The physicochemical characteristics such as weight, thickness, folding endurance, surface pH, drug content and swelling index were evaluated for all formulations. Tensile strength and mucoadhesion studies were carried out with TA.XT plus texture analyser. In vitro drug release studies were carried out in Dissolution apparatus Type VI (cylinder Apparatus). The data was subjected to various kinetic analyses and plotted according to first order, Higuchi and Korsemeyer’s equations to understand the order and mechanism of drug release. Ex-vivo diffusion study through goat buccal mucosa was carried out in Diffusion cell for all the formulations. In-vitro release ex-vivo correlation study was done. In-vivo compatibility study of the buccal patch conducted in 10 healthy human volunteers
Brain-computer interface and visual perception
No full textBrain-Computer Interface (BCI) has been a popular area of research, currently we can find several BCI related product in the market. For example the robotic arms that makes use of BCI.
However, BCI should not be just restricted in controlling robotic limbs and machines, but something that is more between humans, like emotions. The question that the author would like to answer in this project is whether our emotion changes when we look at different images. When we look at a happy photo and sad photo, we felt different emotionally. But is there a difference in our brain signal when we see different things? If yes, is it possible to detect and pick up the differences in term of our brain signal?
In this report, the author will be directing a project in developing a BCI system then find out if there exists a difference in EEG signal and later classify the difference into 1 of the 4 different targeted emotions (Anger, Fear, Happy and Sadness). By using a wireless EEG device, EPOC neuroheadset, to retrieve the EEG signal from a person’s scalp. The author also implements a Matlab script to handle the signal processing tasks in order to obtain the EEG signals.
The author also conducts experiments to test out the BCI system, whether it is capable of classifying the emotion of a person when he/she is looking at images of different objects.Bachelor of Engineering (Computer Engineering
An efficient partial feedback linearization current controller for grid connected photovoltaic system
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