Master of Science

thesisKneeling is a daily activity for some occupations like carpet layers, miners, tile layers, floor layers, electricians, shipbuilders and many others. Several studies have shown that there is an association between kneeling or squatting and development of osteoarthritis of the knee joint. Even though this relationship has been established, few research studies have been conducted to estimate actual knee stresses and the role of kneepads in reducing these stresses while kneeling. Hence, this study looks at estimating the stress on the knees during simulated kneeling work while wearing six different types of kneepads. Custom force sensors were fabricated using FlexiForce™ Sensors and were placed on both knees over anatomically defined landmarks on the patella and tibial tubercle. Ten participants were recruited and consented to perform a series of kneeling tasks. Five wooden platforms were placed in five different locations surrounding two force plates and custom made three-axis load cells where the participants knelt. A set of five lettered, ceramic tiles were given to each participant and randomly placed on each platform with a corresponding letter. Estimated kneeling reaction forces derived from sensor values were used to quantify the effectiveness of each design in reducing the applied forces on the knee joint. Also these forces were used to verify the significance of location on force. The data from both the sensors and the force plates and load cells were analyzed for results. Two-way analysis of variance (ANOVA) with repeated measures, where kneepad and location were the independent variables and calculated applied force was the independent variable was used to analyze the results. There was a significant relationship between force and kneepad and also between force and location. The placement of the sensor on the knee was found to be a major factor for the estimation of the force on the knees. It is apparent that proper kneepad design and selection can be an effective abatement to reduce the stress accumulated on the knee during kneeling work

Neural Machine Translation for Low Resource Languages using Bilingual Lexicon Induced from Comparable Corpora

Resources for the non-English languages are scarce and this paper addresses this problem in the context of machine translation, by automatically extracting parallel sentence pairs from the multilingual articles available on the Internet. In this paper, we have used an end-to-end Siamese bidirectional recurrent neural network to generate parallel sentences from comparable multilingual articles in Wikipedia. Subsequently, we have showed that using the harvested dataset improved BLEU scores on both NMT and phrase-based SMT systems for the low-resource language pairs: English--Hindi and English--Tamil, when compared to training exclusively on the limited bilingual corpora collected for these language pairs.Comment: 8 pages, 3 figures, 4 tables, NAACL-SRW (2018

Engineering metal parallel plate waveguides as a 2-D plane for high resolution THz time domain spectroscopy

Scope and Method of Study: The research summarized in this dissertation is on the investigation of the application of metal parallel plate waveguides (PPWG) for performing high resolution spectroscopic measurements of molecular solids at THz frequencies. The dissertation also presents results on the incorporation of high Q periodic structures within a metal PPWG and their application in sensitive detection of materials by monitoring change in refractive index. The experimental results were obtained by measuring the transmission of metal PPWG with samples in a standard THz time domain spectroscopy system based on photoconductive switches in 4f geometry.Findings and Conclusions: The main finding of this endeavor is that waveguide THz time domain spectroscopy using metal PPWGs can be efficiently applied to extract high resolution vibrational resonances associated with molecular solids. This technique discovered as a part of this research is a new and novel method which for the first time facilitates high resolution spectroscopic measurements of solid microcrystalline films which are easy to make in comparison to single crystal samples, but allows us to extract high resolution vibrational modes of the molecules. This technique can be complimentarily applied with the standard THz-TDS and Fourier transform infra-red spectroscopy to resolve the complete vibrational response of any molecular solid. We have also shown that metal PPWG also allows the incorporation of periodic structures like a weak Bragg stack and be applied as a very high - Q frequency filter having application in chemical sensing. The Q factors obtained by us are among the highest obtained for resonant and periodic structures within waveguide structures. We can conclude that the PPWG acts as an efficient 2-D plane which allows for performing high resolution spectroscopy and for incorporating frequency filtering devices with in the sub wavelength gap