Decentralized MPC based Obstacle Avoidance for Multi-Robot Target Tracking Scenarios

In this work, we consider the problem of decentralized multi-robot target tracking and obstacle avoidance in dynamic environments. Each robot executes a local motion planning algorithm which is based on model predictive control (MPC). The planner is designed as a quadratic program, subject to constraints on robot dynamics and obstacle avoidance. Repulsive potential field functions are employed to avoid obstacles. The novelty of our approach lies in embedding these non-linear potential field functions as constraints within a convex optimization framework. Our method convexifies non-convex constraints and dependencies, by replacing them as pre-computed external input forces in robot dynamics. The proposed algorithm additionally incorporates different methods to avoid field local minima problems associated with using potential field functions in planning. The motion planner does not enforce predefined trajectories or any formation geometry on the robots and is a comprehensive solution for cooperative obstacle avoidance in the context of multi-robot target tracking. We perform simulation studies in different environmental scenarios to showcase the convergence and efficacy of the proposed algorithm. Video of simulation studies: \url{https://youtu.be/umkdm82Tt0M

Solving Combinatorial Optimization Problems Using Genetic Algorithms and Ant Colony Optimization

This dissertation presents metaheuristic approaches in the areas of genetic algorithms and ant colony optimization to combinatorial optimization problems. Ant colony optimization for the split delivery vehicle routing problem An Ant Colony Optimization (ACO) based approach is presented to solve the Split Delivery Vehicle Routing Problem (SDVRP). SDVRP is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) wherein a customer can be visited by more than one vehicle. The proposed ACO based algorithm is tested on benchmark problems previously published in the literature. The results indicate that the ACO based approach is competitive in both solution quality and solution time. In some instances, the ACO method achieves the best known results to date for the benchmark problems. Hybrid genetic algorithm for the split delivery vehicle routing problem (SDVRP) The Vehicle Routing Problem (VRP) is a combinatory optimization problem in the field of transportation and logistics. There are various variants of VRP which have been developed of the years; one of which is the Split Delivery Vehicle Routing Problem (SDVRP). The SDVRP allows customers to be assigned to multiple routes. A hybrid genetic algorithm comprising a combination of ant colony optimization, genetic algorithm, and heuristics is proposed and tested on benchmark SDVRP test problems. Genetic algorithm approach to solve the hospital physician scheduling problem Emergency departments have repeating 24-hour cycles of non-stationary Poisson arrivals and high levels of service time variation. The problem is to find a shift schedule that considers queuing effects and minimizes average patient waiting time and maximizes physicians’ shift preference subject to constraints on shift start times, shift durations and total physician hours available per day. An approach that utilizes a genetic algorithm and discrete event simulation to solve the physician scheduling problem in a hospital is proposed. The approach is tested on real world datasets for physician schedules

Behavior of FRP wrapped concrete cylinders

In this research, increases in strength, stiffness and ductility due to external wrapping of Carbon Fiber Reinforced Polymer (CFRP) sheets on plain and steel reinforced concrete cylinders were studied. The research focused on behavior of plain and wrapped concrete cylinders with respect to parameters such as: (1) concrete compressive strength (fc\u27); (2) fiber orientation of CFRP wrap (0°, 45° and +/-45°); (3) cylinder size (3 x 6 , 4 x 8 , 6 x 12 ); (4) number of CFRP wraps (1, 3, 6); (5) wrapping height and location (top and bottom, middle); (6) degree of fabric wetting; and (7) degree of bonding fabric onto concrete. The mechanical properties evaluated include confinement related increase in axial strength/stiffness, energy absorption (deformability factor), and failure modes. The experimental results were correlated to analytical models consisting of terms representing lateral confining/radial pressure generated by the wrap in hoop direction.;The mechanical properties were compared to those of non-wrapped specimens. An increase in strength of 1.5--3 times and hoop strain of 10--20 times was noticed. The increase in axial strength of 3 x 6 concrete cylinder per layer of wrap for 1, 3 and 6 layer wrapped cylinder was 29%, 43.7% and 33.93%, respectively. Cylinders completely bonded with wrap showed 1.52 times increase in strength whereas cylinders with 31.8% and 21.2% bond showed 1.48 times and 1.23 times increase in strength, respectively. Thus the small delaminations or discontinuities in bonding that may be caused during hand or machine wrapping of column specimens are not critical and do not affect the confinement related strength increase. Deformability factor or energy absorption of specimen wrapped with 3 wraps of 0° fiber direction showed 12 times increase and specimens with +/-45° wrap showed 9 times increase compared to non-wrapped specimens.;Aging of wrapped and non-wrapped cylinders with and without internal steel reinforcement and carbon strip specimens was studied by subjecting them to elevated temperature (175°F) and freeze-thaw (-20°F to 120°F) condition. Wrapped cylinders showed a maximum decrease in strength of 12% in elevated temperature aging and 5% in freeze thaw aging. Further Aging is underway for both conditions.;Non-destructive infrared thermography tests were done to study the interfacial bond between concrete and wrap. Thermograms were recorded to identify the presence of localized delaminations in the wrapped specimens. Infrared thermography was also used to examine delamination size increase in aged specimens, and no detectable growth was observed with thermography

Survey on Hardware Implementation of Montgomery Modular

This paper gives the information regarding different methodology for modular multiplication with the modification of Montgomery algorithm. Montgomery multiplier proved to be more efficient multiplier which replaces division by the modulus with series of shifting by a number and an adder block. For larger number of bits, Modular multiplication takes more time to compute and also takes more area of the chip. Different methods ensure more speed and less chip size of the system. The speed of the multiplier is decided by the multiplier. Here three modified Montgomery algorithm discussed with their output compared with each other. The three methods are Iterative architecture, Montgomery multiplier for faster Cryptography and Vedic multipliers used in Montgomery algorithm for multiplication.Here three boards have been used for the analysis and they are Altera DE2-70, FPGA board Virtex 6 and Kintex 7

Psychophysical Evaluation of Descriptors and Tools for Measurement of Urge-to-Cough Sensation in Healthy Young Adults (HYA)

The studies contained in this dissertation were driven by a desire to improve the methods for sensory testing of cough for clinical research and practice. Two scientific gaps in the cough evaluation literature were identified and investigated using two specific studies on healthy young adult participants. The first study focused on validating an appropriate descriptor for cough sensations (Chapter 2) and the second study (Chapter 3) focused on evaluating magnitude estimation tools to measure cough sensations. The findings of this dissertation make several unique contributions to the cough literature. The first study systematically compared two descriptive responses to cough stimuli (i.e., capsaicin) within subjects in terms of both cough sensory and cough motor outcomes. Findings revealed two types of descriptive responses for capsaicin stimuli, warm/burn and urge-to-cough (UTC). The UTC descriptor was, however, more sensitive and a valid predictor of cough response. The second study systematically compared two magnitude estimation tools, the Modified Borg Scale (MBS) and the generalized Labeled Magnitude Scale (gLMS) to measure the UTC sensations. Findings revealed that both tools were reliable and valid in detecting UTC sensations and predicting cough response. However, a differential effect to detection of UTC sensations across neighboring stimuli concentrations were demonstrated by the two tools. This dissertation provides the first set of normative reference values for UTC responses across a wide range of sensory continua using the conventional metric, the MBS, and an additional metric, the gLMS. Limitations are acknowledged and future work is suggested

Survey on Hardware Implementation of Montgomery Modular

This paper gives the information regarding different methodology for modular multiplication with the modification of Montgomery algorithm. Montgomery multiplier proved to be more efficient multiplier which replaces division by the modulus with series of shifting by a number and an adder block. For larger number of bits, Modular multiplication takes more time to compute and also takes more area of the chip. Different methods ensure more speed and less chip size of the system. The speed of the multiplier is decided by the multiplier. Here three modified Montgomery algorithm discussed with their output compared with each other. The three methods are Iterative architecture, Montgomery multiplier for faster Cryptography and Vedic multipliers used in Montgomery algorithm for multiplication.Here three boards have been used for the analysis and they are Altera DE2-70, FPGA board Virtex 6 and Kintex 7

Cross finger flap cover for fingertip injuries

Background: Fingertip injuries are the most common form of hand injuries. Restoration of the anatomy is a technical challenge and is one of the basic tenets of the management of fingertip injuries. The cross finger flap is simple and easy to do and is a very useful tool in reconstruction of the pulp of the finger. The project aimed to study the efficacy of cross finger flap in the coverage of fingertip injuries.Methods: The study was conducted on a prospective basis in Sri Ramachandra University Hospital in Chennai. The study period was from May 2013 to August 2016.  All adults who had fingertip injuries who had undergone cross finger flap cover were included in the study. Patients who had other flaps for reconstruction and who were lost for follow-up were excluded from the study. Preoperative parameters which were recorded were mechanism of injury, size of defect, size of the flap, location of donor site and method of coverage of secondary defect. Outcome measures recorded were flap viability, flap sensibility using two-point discrimination, range of motion of fingers, grip strength and presence of other complications.Results: 40 patients were included in the study. Six were lost for follow-up. Mean follow-up was 14 months.  All flaps survived. Full range of motion was obtained in 87% of patients. Average grip strength was 94% for dominant hand injuries and 78% for non-dominant hand injuries. Mean quick DASH score was 10.5. Mean two-point discrimination was 15.4 mm. Conclusions: Cross finger flap is very effective for coverage of volar fingertip defects with minimal residual problems

New drug development in India

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Isolation and Identification of Candida from the Oral Cavity

Various techniques are available for the isolation of Candida within the oral cavity. Such methods play an important role in the diagnosis and management of oral candidosis. The growing importance of Candida is in part related to the emergence of HIV infection and the more widespread use of immunosuppressive chemotherapy. Along with the Candida albicans there has been a greater recognition of the importance of the nonalbicans Candida species in oral candidosis. Identification of infecting strains of Candida is important because isolates of Candida species differ widely, both in their ability to cause infection and also in their susceptibility to antifungal agents. Thus this review provides an overview of the reliable methods of candidal isolation and identification of isolates from the oral cavity