Master of Science

thesisCurrently, few methods exist to accurately model a human motion inside a monitored area. Most of the approaches that exist depend on some kind of boolean data from sensors that tell the presence or absence of person a at a given instant of time near a particular sensor. Using that information, some systems can then track a person across the area at di erent timestamps. Furthermore, for most existing approaches, the accuracy drops rapidly as the number of persons in the image increases. The sensors used in such settings are usually expensive. Not much work has been done to build a similar system based on inexpensive radio sensors. As there is no way for our radio sensors to provide information as to whether a person is present at a location, we need to extract it from the data using computer vision and machine learning techniques. However, it is not easy in such a system to model the noise component accurately. Therefore, we provide a probabilistic model to decide whether a detected blob is noise or an actual person. In our work, we exploit the fact that images do not change by much between successive timeframes and use this to detect and track multiple persons in a monitored area with a reasonably high accuracy. We use location and count of persons in historical images, and their similarity with the current image to calculate the new locations and count

Comparative Study of Laparoscopic Cholecystectomy Versus Open Cholecystectomy in Elderly Patients: An Observational Comparative Study

Background: Surgery for cholelithiasis is more common in elderly patients as the incidence of gallstones increases with age. Age is one of the critical factors affecting the mortality and morbidity rates after open cholecystectomy (OC). The aim of this report was to evaluate and comparing the outcome of laparoscopic cholecystectomy (LC) in elderly patients (≥ 65 years old) with that of OC.Methods: A prospective observational comparative study was conducted in the Department of General Surgery at R.G. Kar Medical College and Hospital, India, from January 2012 to June 2013. 50 patients were involved. Group 1 had patients planned for conventional LC, i.e., LC group and Group 2 with OC, i.e., OC group. Patients included were the cases who aged 65 years and above, with symptomatic gallstone disease, with asymptomatic gallstone with associated illnesses or with anticipated complications. Various variables were compared intraoperatively and postoperatively.Results: Significant differences were seen in LC group with more duration of surgery than OC group. The pain score was significantly low in LC group after 6 and 24 hours. The duration of hospital stay was also significantly less in LC group. Pulmonary function tests were done on 1st and 6th post-operative days showed a significant difference of peak expiratory flow rate, forced expiratory volume1, and forced vital capacity between LC and OC on 1st post-operative day.Conclusions: LC should be advised for elderly patients as an elective procedure safely as post-operative morbidity is much less in LC compared to the OC

A NOVEL ALGORITHM BASED ON CASCADING OF NEURAL NETWORK MODELS AND WAVELET TRANSFORM FOR IMAGE ENHANCEMENT.

Image enhancement and restoration is pre-request of computer vision. The distortion and degradation of image suffered the process of pattern matching and quality of image. Wavelet is very important transform function play a role in image enhancement and image de-noising. The concept of wavelet used as soft thresholding and hard thresholding. A processing of data through wavelet is very efficient in process of neural network. In this paper we discuss the proposed algorithm for image enhancement based on self organized map network and wavelet transform. Basically self organized map network is unsupervised training mechanisms of pattern, due to this reason the processing of network is very fast in compression of another artificial neural network method. And the combination of wavelet and self organized map network have great advantage over conventional method such as histogram equalization and multi-point histogram equalization and another conventional technique of image enhancement

Temporary and Permanent Buyout Prices in Online Auctions

Increasingly used in online auctions, buyout prices allow bidders to instantly purchase the item listed. We distinguish two types: a temporary buyout option disappears if a bid above the reserve price is made; a permanent one remains throughout the auction or until it is exercised. In a model featuring time-sensitive bidders with uniform valuations and Poisson arrivals but endogenous bidding times, we focus on finding temporary and permanent buyout prices maximizing the seller's discounted revenue, and examine the relative benefit of using each type of option in various environments. We characterize equilibrium bidder strategies in both cases and then solve the problem of maximizing seller's utility by simulation. Our numerical experiments suggest that buyout options may significantly increase a seller’s revenue. Additionally, while a temporary buyout option promotes early bidding, a permanent option gives an incentive to the bidders to bid late, thus leading to concentrated bids near the end of the auction.Singapore-MIT Alliance (SMA

Buyout prices in online auctions

Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2006.Includes bibliographical references (p. 149-154).Buyout options allow bidders to instantly purchase at a specified price an item listed for sale through an online auction. A temporary buyout option disappears once a regular bid above the reserve price is made, while a permanent option remains available until it is exercised or the auction ends. Buyout options are widely used in online auctions and have significant economic importance: nearly half of the auctions today are listed with a buyout price and the option is exercised in nearly one fourth of them. We formulate a game-theoretic model featuring time-sensitive bidders with independent private valuations and Poisson arrivals but endogenous bidding times in order to answer the following questions: How should buyout prices be set in order to maximize the seller's discounted revenue? What are the relative benefits of using each type of buyout option? While all existing buyout options we are aware of currently rely on a static buyout price (i.e. with a constant value), what is the potential benefit associated with using instead a dynamic buyout price that varies as the auction progresses?(cont.) For all buyout option types we exhibit a Nash equilibrium in bidder strategies, argue that this equilibrium constitutes a plausible outcome prediction, and study the problem of maximizing the corresponding seller revenue. In particular, the equilibrium strategy in all cases is such that a bidder exercises the buyout option provided it is still available and his valuation is above a time-dependent threshold. Our numerical experiments suggest that a seller may significantly increase his utility by introducing a buyout option when any of the participants are time-sensitive. Furthermore, while permanent buyout options yield higher predicted revenue than temporary options, they also provide additional incentives for late bidding and may therefore not be always more desirable. The numerical results also imply that the increase in seller's utility (over a fixed buyout price auction) enabled by a dynamic buyout price is small and does not seem to justify the corresponding increase in complexity.by Shobhit Gupta.Ph.D

T-STAG: resource and web-interface for tissue-specific transcripts and genes

T-STAG (tissue-specific transcripts and genes) is a resource and web-interface, designated to analyze tissue/tumor-specific expression patterns in human and mouse transcriptomes. It integrates our refined prediction of specific expression patterns both in genes as well as in individual isoforms with man–mouse orthology data. In combination with the features for combining/contrasting the genes expressed in different tissues, T-STAG implicates important biological applications, such as the detection of differentially expressed genes in tumors, the retrieval of orthologs with significant expression in the same tissue etc. Additionally, our refined categorization of expressed sequence tags (ESTs) according to the normalization of cDNA libraries allows searching for putative low-abundant transcripts. The results are tightly linked to our visualization tools, GeneNest (expression patterns of genes) and SpliceNest (gene structure and alternative splicing). The user-friendly interface of T-STAG offers a platform for comprehensive analysis of tissue and/or tumor-specific expression patterns revealed by the EST data. T-STAG is freely accessible at

Evaluation of anti-anxiety activity of Mucuna pruriens

Mucuna pruriens, also known as Velvet Bean, Mucuna pruriens has been used for centuries by Ayurvedic herbalists for overall wellness. Mucuna pruriens provides support for brain function, muscle health and libido. Mucuna pruriens has also been shown to have diuretic effects. It increases tissue resiliency and improves coordination. Mucuna can also increase testosterone levels, which in turn can lead to increased muscle mass and strength. It also supports the nervous and reproductive systems in the body. anti-oxidant activity of M. pruriens has been also demonstrated in vitro by its ability to scavenge DPPH radicals and reactive oxygen species. This is an excellent natural source of L-dopa and 5-hydroxy tryptophan (5-HT) Present study was designed to evaluate the anti-anxiety activity of Mucuna pruriens extract in Swiss albino mice. Three doses of Mucuna pruriens (100, 200,400 mg/kg, p.o.) and standard dose of Buspirone (5 mg/kg, i.p.) were used for evaluation of the anti-anxiety activity. The elevated plus maze (EPM) was used to take as a measure of antianxiety effect. Mucuna pruriens at the doses of 200 mg/kg and 400 mg/kg significantly reduced the time spent and no. of entries in closed arm, increased the time spent and entries into open arm in elevated plus maze (p<0.05) as compared to control group. These results indicate that MP may be possesses antianxiety property. Keywords:  Anxiety, Elevated plus maze, Mucuna pruriens, Buspirone, Swiss Albino Mice

Effect of Shilajit on Amnesia

Shilajit is a herbo-mineral drug, has been referred to as memory enhancer. donepezil is prescribed to treat   mild to moderate dementia, amnesia, and cognitive disorders. Midzolam is known to produce anterograde amnesia in human and animals. The present study is framed to investigate the effect of Shilajit and Donepezil on Midzolam induced experimental amnesia using elevated plus maze test in mice. Twelve groups of mice were used and each group involved of six mice. Midzolam (2 mg kg -1), shilajit (100 mg kg-1), Donepezil (3 mg kg) and distilled water (as vehicle) (10 ml kg-1) were injected intraperitoneally (ip) in different groups of mice 30 min before the training and immediate after the training. Each mouse was naïve to elevate plus maze for 90 sec. The time taken by the animals to move from the open arms to either of two sides of enclosed arms was recorded. All the results were expressed as mean±S.E.M and P<0.05 considered as statistically significant. Midzolam treated animals exhibit significant increase in transfer latency time. On the other hand, shilajit and Donepezil treated mice shown significant decrease in transfer latency time. Simultaneously, animals treated with shilajit (100 mg kg-1 i.p.) and Donepezil (3 mg kg-1 i.p.) significantly exhibit decrease in transfer latency time measured after 24 hrs in the animals previously treated with Midzolam (2 mg kg-1 i.p.). The above observations revels that Midzolam impair learning, shilajit and Donepezil improve acquisition. The results also indicate that shilajit and Donepezil prevent Midzolam induce learning impairment. It may be concluded that shilajit and Donepezil reverse Midzolam induced amnesia by the same mechanism i.e. improvement in cholinergic or dopaminergic activity, at least in mice species. Key words:  Shilajit, Donepezil, Midzolam, Amnesia, Elevated plus maze, Mic

Robust millisecond coherence times of erbium electron spins

Erbium-doped solids are prime candidates for optical quantum communication networks due to erbium's telecom C-band emission. A long-lived electron spin of erbium with millisecond coherence time is highly desirable for establishing entanglement between adjacent quantum repeater nodes while long-term storage of the entanglement could rely on transferring to erbium's second-long coherence nuclear spins. Here we report GHz-range electron spin transitions of $^{167}\mathrm{Er}^{3+}$ in yttrium oxide ($\mathrm{Y_2O_3}$) matrix with coherence times that are consistently longer than a millisecond. Instead of addressing field-specific Zero First-Order Zeeman transitions, we probe weakly mixed electron spins with the field orientation along the lower g-factors. Using pulsed electron spin resonance spectroscopy, we find paramagnetic impurities are the dominant source of decoherence, and by polarizing them we achieve a Hahn echo spin $\mathrm{T_2}$ up to 1.46 ms, and a coherence time up to 7.1 ms after dynamical decoupling. These coherence lifetimes are among the longest found in crystalline hosts especially those with nuclear spins. We further enhance the coherence time beyond conventional dynamical decoupling, using customized sequences to simultaneously mitigate spectral diffusion and Er-Er dipolar interactions. Despite nuclear and impurity spins in the host, this work shows that long-lived erbium spins comparable to non-nuclear spin hosts can be achieved. Our study not only establishes $^{167}\mathrm{Er}^{3+}$: $\mathrm{Y_2 O_3}$ as a significantly promising quantum memory platform but also provides a general guideline for engineering long-lived erbium spins in a variety of host materials for quantum technologies.Comment: 10 pages, 4 figure

Quantifying similarity between motifs

A common question within the context of de novo motif discovery is whether a newly discovered, putative motif resembles any previously discovered motif in an existing database. To answer this question, we define a statistical measure of motif-motif similarity, and we describe an algorithm, called Tomtom, for searching a database of motifs with a given query motif. Experimental simulations demonstrate the accuracy of Tomtom's E values and its effectiveness in finding similar motifs