Learning Local Features Using Boosted Trees for Face Recognition

Face recognition is fundamental to a number of significant applications that include but not limited to video surveillance and content based image retrieval. Some of the challenges which make this task difficult are variations in faces due to changes in pose, illumination and deformation. This dissertation proposes a face recognition system to overcome these difficulties. We propose methods for different stages of face recognition which will make the system more robust to these variations. We propose a novel method to perform skin segmentation which is fast and able to perform well under different illumination conditions. We also propose a method to transform face images from any given lighting condition to a reference lighting condition using color constancy. Finally we propose methods to extract local features and train classifiers using these features. We developed two algorithms using these local features, modular PCA (Principal Component Analysis) and boosted tree. We present experimental results which show local features improve recognition accuracy when compared to accuracy of methods which use global features. The boosted tree algorithm recursively learns a tree of strong classifiers by splitting the training data in to smaller sets. We apply this method to learn features on the intrapersonal and extra-personal feature space. Once trained each node of the boosted tree will be a strong classifier. We used this method with Gabor features to perform experiments on benchmark face databases. Results clearly show that the proposed method has better face recognition and verification accuracy than the traditional AdaBoost strong classifier

Audio watermarking using transformation techniques

Watermarking is a technique, which is used in protecting digital information like images, videos and audio as it provides copyrights and ownership. Audio watermarking is more challenging than image watermarking due to the dynamic supremacy of hearing capacity over the visual field. This thesis attempts to solve the quantization based audio watermarking technique based on both the Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). The underlying system involves the statistical characteristics of the signal. This study considers different wavelet filters and quantization techniques. A comparison is performed on diverge algorithms and audio signals to help examine the performance of the proposed method. The embedded watermark is a binary image and different encryption techniques such as Arnold Transform and Linear Feedback Shift Register (LFSR) are considered. The watermark is distributed uniformly in the areas of low frequencies i.e., high energy, which increases the robustness of the watermark. Further, spreading of watermark throughout the audio signal makes the technique robust against desynchronized attacks. Experimental results show that the signals generated by the proposed algorithm are inaudible and robust against signal processing techniques such as quantization, compression and resampling. We use Matlab (version 2009b) to implement the algorithms discussed in this thesis. Audio transformation techniques for compression in Linux (Ubuntu 9.10) are applied on the signal to simulate the attacks such as re-sampling, re-quantization, and mp3 compression; whereas, Matlab program for de-synchronized attacks like jittering and cropping. We envision that the proposed algorithm may work as a tool for securing intellectual properties of the musicians and audio distribution companies because of its high robustness and imperceptibility

RAJKIRAN NATARAJAN

Many research questions in dysphagia research require frame-by-frame annotation of anatomical landmarks visible in videofluorographs as part of the research workflow, which can be a tedious and error prone process. Such annotation is done manually using image analysis tools, is error prone, and characterized by poor rater reliability. In this thesis, a computer-assisted workflow that uses a point tracking technique based on the Kanade-Lucas-Tomasi tracker to semi-automate the annotation process, is developed and evaluated. Techniques to semi-automate the annotation process have been explored but none have had their research value demonstrated. To demonstrate the research value of a workflow based on point tracking in enhancing the annotation process, the developed workflow was used to perform an enhanced version of the recently published Coordinate Mapping swallowing study annotation technique to determine several swallowing parameters. Evaluation was done on eight swallow studies obtained from a variety of clinical sources and showed that the workflow produced annotation results with clinically insignificant spatial errors. The workflow has the potential to significantly enhance research processes that require frame-by-frame annotation of anatomical landmarks in videofluorographs as part of their data preparation steps, by reducing the total time required to annotate clinical case

Multi Attacker Collision Analysis In MANETs Using Conditional likilihood

Mobile ad hoc networks will aim to provide services to the wireless network without depending on any fixed infrastructure There are basically two approaches to motivate players: 1) by denying service to misbehaving players by means of a reputation mechanism or 2) by remunerating honest players, using for example a micropayment scheme. In these works, malicious players are modelled as never cooperative, without any further sophistication, since their main focus was discouraging selfish players. There is no degree of selfishness that can approximate the behaviour of malicious players. This work will focus on multi-attacker collusion in the regular/malicious player game. The Proposed System also model the regular/malicious player game as a multistage dynamic Bayesian signalling game to find the optimal strategy of regular and malicious players. Apart from that utility function, degree of selfishness of a player and degree of uncertainty are also considered

Constraint based personalization

Personalization is defined as a process that facilitates interaction among consumers and providers such that individual consumers are enabled to more readily access the content and services of providers, and individual providers are enabled to more effectively and easily deliver their content and services to consumers. This project presents a personalization framework for web and e-business applications that builds on the architectural model presented by In.stone in [3] as well as foundation work presented by Toth in [1]. This personalization framework incorporates consumer-provider attributes; considers system/network variables; and models personalization as a constraint-based problem. An initial working prototype constraint engine for processing personalization preferences is also built for a prolific messaging application. In this messaging application users collaborate with each other and with web applications using email, instant messaging and short text messaging services employing their PCs, Personal Digital Assistants (PDAs) and cell phones. The users define all the communication channels have a single ID for all their communication channels. manage their messaging channels by defining preferences 011 how to use their channels. These preferences are then processed by the application through the constraint engine to personalize their communication through the messaging channels

Comparison of the force deterioration of different orthodontic elastomeric materials in artificial saliva: An in vitro study

The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of increased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of orthodontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticeable force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads

Comparison of the force deterioration of different orthodontic elastomeric materials in artificial saliva: An in vitro study

The orthodontist must be able to choose an elastic band with force-extension characteristics that are most suitable for the particular tooth movement required. From a clinician view it would be mandatory not only to know the clinical aspect of these elastics but also their basic properties, in order to extract the most out of these polymers. Stretching of elastics are thought to be the primary cause of force degradation of orthodontic elastics but there is evidence of increased force degradation of elastics when exposed to various types of substances like artificial saliva, phosphoric acid and citric acid. Orthodontic elastics have received mixed reactions of practitioners as reported by the vendors of orthodontic supplies. The present study is designed to compare the force deterioration of different orthodontic elastomeric materials in artificial saliva medium. There was a force deterioration over time in all materials, being greatest on the seventh day of the experiment, especially more in the chains; From the third to the fourth week there was no noticeable force degradation in either group; By the end of the experiment, modules showed less deterioration of the force compared to the chains and threads

Depth Profiles of Residual Stresses in Inconel 718Machined with Uncoated and Coated Tools

567-573Inconel 718 is one of the super-alloy materials, belonging to nickel-chromium alloy family, which has major applications in aerospace sector such as engine parts and turbine components. Durability of these components during engineering performance is affected by residual stresses induced in them in the course of their manufacturing processes. The concept of the present paper is to provide an insight view of induced residual stresses in Inconel 718 work piece, when machined with coated (TiN) and uncoated tools at optimum conditions. For this purpose, turning experiments have been conducted on IN718 material through statistical approach using L9 orthogonal array. Taguchi optimization method is exercised with the emphasis on minimizing the cutting forces resulted during machining. The residual stresses generated in the work piece at the optimum conditions employed for both the tools have been evaluated using XRD method. Conditions such as cutting speed of 60 m/min, feed at 0.068 mm/rev and depth-of-cut of 0.10 mm have been optimized for achieving minimum cutting forces during machining of IN 718 using both coated and uncoated tools. However, tensile stresses on the initial surface layer and compressive stresses in the sub-surface layers are found higher in the work piece material machined with uncoated tool. Surface roughness and temperature developed on the surface of the machined bar are higher in case of uncoated tool than those with coated tool

Work-related musculoskeletal disorders among dentists and their prevention through ergonomic interventions - A systematic review

Introduction: Occupational or work-related musculoskeletal disorders (WMSDs) vastly prevail among dental professionals. This review aims to summarize the prevalence of WMSDs and ergonomic interventions for the prevention of WMSDs among dental professionals. Methods: Thorough literature search was done using scientific databases. The terms musculoskeletal disorders among dentists/dental professionals/ hygienists in dentistry, occupational or work-related MSDs, ergonomics, ergonomic interventions, and several combinations were used as keywords. Articles published in the English language only were included. Abstracts, thesis work, and other languages were excluded. Results: Our findings revealed several studies showing the prevalence of WMSD among dental professionals and ergonomic interventions to prevent MSDs among dental professionals. Conclusion: Dental practice is highly challenging both in terms of physical and mental status there is a need for continuing efforts to discover innovative preventive strategies, to reduce the prevalence of WMSDs. This article guides dental professionals to incorporate the proper ergonomic methods in their early stages of day-to-day work, for long-term and healthy dental practice.