Amita Kapoor

An approach for the recognition of low resolution grey scale facial images using cloud Hopfield neural network (CHNN) is presented. This approach consists of three steps: first we transform the grey scale facial images into binary facial images using Otsu's method, second Hebb rule is employed to store binary faces in the weight matrix of the network and finally correct face is retrieved from distorted face using CHNN retrieval algorithm. CHNN consists of clouds each with r number of unique… Show more

An approach for the recognition of low resolution grey scale facial images using cloud Hopfield neural network (CHNN) is presented. This approach consists of three steps: first we transform the grey scale facial images into binary facial images using Otsu's method, second Hebb rule is employed to store binary faces in the weight matrix of the network and finally correct face is retrieved from distorted face using CHNN retrieval algorithm. CHNN consists of clouds each with r number of unique neurons, these clouds are updated asynchronously unlike conventional asynchronous retrieval in which only one neuron is updated at a time. We compare our results with that of conventional HNN and other face recognition methods. Our results show that even when the distortion in the presented face is 45%, the CHNN is able to give at least 82.8% successful retrieval as compared to only 63% by conventional HNN for the same amount of distortion. This is much greater than previous reported claims to the best of our knowledge. Show less

n this paper we present modifications in the dynamics of Hopfield neural network. We compare our modified retrieval algorithms with both synchronous and asynchronous retrieval algorithms used in Hopfield dynamics. Our results show that a modified Hopfield neural network consisting of a cloud with r number of unique neurons, (in the simulation given in this paper r=3% i.e. 4 neurons out of total 120) is better in terms of both retrieval capabilities and convergence time in comparison to the… Show more

n this paper we present modifications in the dynamics of Hopfield neural network. We compare our modified retrieval algorithms with both synchronous and asynchronous retrieval algorithms used in Hopfield dynamics. Our results show that a modified Hopfield neural network consisting of a cloud with r number of unique neurons, (in the simulation given in this paper r=3% i.e. 4 neurons out of total 120) is better in terms of both retrieval capabilities and convergence time in comparison to the asynchronous retrieval algorithm. Moreover, unlike synchronous retrieval algorithm it does not enter oscillation states. Show less

Advancements in information technology today have made a paradigm shift in teaching as well as learning process. Technology supports both teaching and learning and thus infuses classrooms with various learning tools, such as computers and hand held devices and learning materials developed in form of animations, videos, manuals and presentations. Technology has made learning a very easy process which is available to the students for round the clock. Being knowledge partners it is our obligation… Show more

Advancements in information technology today have made a paradigm shift in teaching as well as learning process. Technology supports both teaching and learning and thus infuses classrooms with various learning tools, such as computers and hand held devices and learning materials developed in form of animations, videos, manuals and presentations. Technology has made learning a very easy process which is available to the students for round the clock. Being knowledge partners it is our obligation not only to guide the students to correct resources but also contribute towards evolution & development of such resources. In the present work, an e-learning based model has been developed for effective teaching of basic electronics experiments. The work includes demonstration of various electronics experiments based on digital and analog electronics by developing various e-manuals, power point presentations, descriptive animations and videos shot in the practical laboratories of the college. These resources would act as a handy tool for anyone who wishes to perform these experiments and will be a stepping stone in the realm of practical based learning for forthcoming students of science. Show less

The paper contains the description of entire process of development of e-learning module including animations, videos and power point presentations of various devices used in electronics practical laboratories by science and engineering students in India. In this work, we have focused on using multimedia technology as an innovative teaching and learning strategy in a problem-based learning environment. The work presented in this paper shows the use of e-learning based approach to make learning… Show more

The paper contains the description of entire process of development of e-learning module including animations, videos and power point presentations of various devices used in electronics practical laboratories by science and engineering students in India. In this work, we have focused on using multimedia technology as an innovative teaching and learning strategy in a problem-based learning environment. The work presented in this paper shows the use of e-learning based approach to make learning of electronics practical more effective and interesting. Show less

This paper presents the development, use and impact of e-learning resources on undergraduate girl students. The paper compares the conventional method of teaching vs the use of ICT tools for teaching. An interesting component of our study is that the ICT tools have been developed by students themselves under the guidance of a teacher.

Erbium doped fiber amplifier is a key device in WDM/DWDM technology. The task of modeling EDFA is computationally expensive. In this paper we investigate the application of multilayered feed-forward neural network to model an EDFA.

Two selected applications of semiconductor optical amplifiers (SOA) are discussed, namely linear in-line amplification in gigabit passive optical networks and fast nonlinear all-optical signal processing. We report on measurements demonstrating the suitability of quantum-dot (QD) and bulk SOA for the respective application areas. For in-line amplification the saturation power of the SOA should be large, while it has to be low for efficient signal processing. For bulk SOA we find by… Show more

Two selected applications of semiconductor optical amplifiers (SOA) are discussed, namely linear in-line amplification in gigabit passive optical networks and fast nonlinear all-optical signal processing. We report on measurements demonstrating the suitability of quantum-dot (QD) and bulk SOA for the respective application areas. For in-line amplification the saturation power of the SOA should be large, while it has to be low for efficient signal processing. For bulk SOA we find by physically-based simulations that at large injection currents and for a fixed gain, p-doping (n-doping) of the active layer increases (decreases) the saturation power. Recently published experiments show that qualitatively these results carry over to QD-SOA. Show less

Semiconductor optical amplifiers (SOAs) can be used as linear in-line amplifiers for extended-reach passive optical networks, or as gain/phase-switchable devices. For these applications, gain, bandwidth and saturation power are important. The saturation power can be increased by decreasing the confinement factor and by increasing the length such that the overall gain remains constant. In this paper we investigate the saturation characteristics of 1.55μm InGaAsP-InP bulk SOA. We do so by using… Show more

Semiconductor optical amplifiers (SOAs) can be used as linear in-line amplifiers for extended-reach passive optical networks, or as gain/phase-switchable devices. For these applications, gain, bandwidth and saturation power are important. The saturation power can be increased by decreasing the confinement factor and by increasing the length such that the overall gain remains constant. In this paper we investigate the saturation characteristics of 1.55μm InGaAsP-InP bulk SOA. We do so by using the physically based simulation tool ATLAS. The simulation tool ATLAS supports simulation of semiconductor lasers only, however making the mirror reflectivities small, the lasing threshold is increased such that lasers are essentially reduced to amplifiers. Next, for investigating the saturation characteristics of SOA, the amplifier gain should be influenced by injecting an optical light power. However, ATLAS cannot simulate the required source directly. Instead, we use in the electron rate equation simultaneously two competing independent models for spontaneous radiative recombination, namely the so-called general model (total recombination rate BnT p with bimolecular recombination coefficient B, electron and hole concentrations nT and p) and the standard model for recombination due to amplified spontaneous emission into the mode under consideration. In the photon rate equation, only the standard model is used. We then increase B, and thus simulate a decrease of the carrier concentration that would physically result from an external optical signal. We show that under conditions of constant injection current and device length an n-doping (p-doping) of the active layer increases (decreases) the input saturation power. In addition we observe that for constant injection current and amplifier gain, a p-doping (n-doping) of the active layer increases (decreases) both the input and output saturation powers because of an reduced (slightly increased) Auger-dominated carrier lifetime. Show less

We report the design criteria for the use of long period gratings (LPGs) as refractive-index sensors with output power at a single interrogating wavelength as the measurement parameter. The design gives maximum sensitivity in a given refractive-index range when the interrogating wavelength is fixed. Use of the design criteria is illustrated by the design of refractive-index sensors for specific application to refractive-index variation of a sugar solution with a concentration and detection of… Show more

We report the design criteria for the use of long period gratings (LPGs) as refractive-index sensors with output power at a single interrogating wavelength as the measurement parameter. The design gives maximum sensitivity in a given refractive-index range when the interrogating wavelength is fixed. Use of the design criteria is illustrated by the design of refractive-index sensors for specific application to refractive-index variation of a sugar solution with a concentration and detection of mole fraction of xylene in heptane (paraffin). Show less

The coupled differential equations, which govern the evolution of pump and signal power in the gain characterization of Er-doped diffused channel waveguides, involve integrals that depend explicitly on the modal fields at the pump and all signal wavelengths. We use an analytical form of the modal field as an appropriately chosen buried asymmetric Gaussian function centered at the field maximum; this leads to analytical forms of coupled differential equations with no integrals for the… Show more

The coupled differential equations, which govern the evolution of pump and signal power in the gain characterization of Er-doped diffused channel waveguides, involve integrals that depend explicitly on the modal fields at the pump and all signal wavelengths. We use an analytical form of the modal field as an appropriately chosen buried asymmetric Gaussian function centered at the field maximum; this leads to analytical forms of coupled differential equations with no integrals for the calculation of gain characteristics of the amplifying waveguide. Thus, computations are simplified and computation time is also significantly reduced Show less