18 research outputs found
Topics on electron,neutrino and axion scattering
No full textThesis: S.M., Massachusetts Institute of Technology, Department of Physics, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from PDF version of thesis.Includes bibliographical references (pages 61-64).Under the broad topic of scattering, in this thesis we particularly investigate Lorentz invariance using Compton Scattering at the Compton Polarimeter located in Hall-C at Thomas Jefferson National Accelerator Facility. The Mississippi State Axion Search, an axion search experiment which uses light shining through a wall technique is described in detail, including its instrumentation, initial tests and future impact. Furthermore, a novel method of detection of solar anti-neutrinos based on coherent neutrino scattering is described. Additionally, on the instrumentation side, development of a multi-purpose beam instrument based on synchrotron light to measure the electron beam polarization, beam profile and intensity at the future Electron Ion Collider is presented.by Prajwal Mohanmurthy.S.M
MDO framework for university research collaboration: AGILE academy initiatives & outcomes
No full textAGILE Project is developing the 3rd generation MDO processes, which will support the development of the next generation aerospace products. The establishment of effective collaborative design methodologies is currently acknowledged as the key enabler for future product development processes. At the same time, the need to introduce collaborative design techniques within educational activities is also well recognized by the Academic, Research and Industrial communities. AGILE project supported by European Commission’s H2020 Programme, is setting the “AGILE Paradigm”, a conceptual framework which contains all the elements to implement a multidisciplinary collaborative design network. The AGILE Academy initiative is conceived to infuse into the Academic organizations and educational environments the “AGILE Paradigm”, and make available all the technologies developed within the AGILE Project, which support the implementation of such a Paradigm. This paper focus is on the inception, approach and results of the AGILE Academy participants from several universities around the world
Low-cost uni-directional PFC for 3-phase systems
No full textPower consumed by any equipment connected to the grid must be regulated to facilitate the reliable and efficient operation of the grid and for smooth equipment operation of other consumers. Power factor is one of the major power quality measurement tool. All the electrical equipment connected to the grid must comply with the power factor limits as specified under various standards. This thesis aims at the development of a cost-effective power factor correction converter for a motor drive with a power range up to 10 kW, which is also robust for line and load transients.Electrical Engineerin
Cylinder Drag Reduction Using Discrete Surface Roughness: An Experimental Investigation Into the Effect of Cylindrical Roughness Elements
No full textThis thesis investigates the influence of Cylindrical Distributed Roughness Elements (polka-dots) on cylinder flow, with a focus on potential applications in sports aerodynamics. The primary goals are twofold: to explore the mechanism behind tripping and to analyse how the dimensions (height, width, spacing) of polka-dots affect flow characteristics. The research employs an experimental approach, utilising balance measurements to quantify drag within the relevant Reynolds number range experienced by the limbs of speed-skaters. Additionally, Particle Image Velocimetry (PIV) measurements are conducted to examine the boundary layer and wake flow, revealing insights into how different polka-dot geometries impact flow characteristics.11 polka-dot configurations were tested wherein the polka-dot height, diameter and spanwise (flow-normal) spacing was varied. Two PIV domains were imaged: the boundary layer flow before and after the polka-dot (covering an azimuthal range of about 40◦ of the circular profile), and the wake domain of the cylinder (about 2 diameters into the downstream flow). The boundary layer flow images were used to characterise the flow seen by the polka-dot array, and how it is affected by changes in the polka-dot geometry. The wake domain PIV imagery was used to examine the shape and dimensions of the cylinder wake.Among the 11 tested polka-dot configurations, 10 effectively triggered drag reduction to varying extents within the relevant regime. The minimum drag coefficient was achieved by the configuration with the polka-dots of greatest diameter. It was also seen that increasing polka-dot height is likely to cause premature separation which is further exacerbated by a narrower polka-dot spacing. In general, results indicate that shorter and wider polka-dots cause transition at lower Reynolds numbers, and a greater reduction in drag occurs when transition takes place at higher Reynolds numbers. Polka-dots placed in closer proximity initiate flow tripping earlier, while wider spacing results in more substantial drag reduction. However, it is observed that the polka-dots, when spaced closer together, see a lower flow velocity for the same polka-dot height and may lead to premature separation.In terms of the wake width, a high linear correlation is seen between the measured wake width and the measured coefficient of drag (r2 ≈ 0.9). It is also seen that for drag coefficient values close to the minimum drag coefficient value, the wake width sees minimal change. The change in wake geometry is then seen as a change in the wake tapering (downstream decrease of the wake width) and the streamwise wake length. Therefore, a larger wake imaging domain in the streamwise direction is likely to allow for a more accurate correlation of the wake geometry and the drag coefficient.While the study offers valuable insights, several recommendations are put forth for further research. Expanding the wake imaging domain is suggested to enhance correlations with the drag coefficient, and investigating spanwise flow variations would provide deeper insight into the tripping mechanism.Aerospace Engineering | Aerodynamic
Influence of Parametric Modelling of Wing Subsystems on the Aircraft Design and Performance
No full textAircraft design methodologies have been significantly developing from the past few years with the advancements in knowledge based techniques. These methods enable the storage of design knowledge and rules, and reuse them to create different types of designs, thus preventing the designer to perform repetitive tasks. Tasks such as parametric modelling of components, such as the aircraft wing can be automated by storing the modelling processes and the design rules in a knowledge base. With this process, variants of the wing with different geometric parameters can then be generated in a short duration by simply varying certain top-level requirements. It is necessary to extend these design techniques to model aircraft systems in the conceptual design stage. This, not only decreases the time of design realisation but also presents a scope to assess the effects of various inter-dependencies due to systems and make appropriate changes, in the early stages of aircraft design. Developing and demonstrating a framework which aids to assess the influence of the wing subsystems, namely the flight control actuators, fuel tanks and anti-ice elements; on the aircraft design and performance in the conceptual design stage is the aim of the thesis. This thesis presents a combination of physics based and knowledge based design methodologies to size the wing subsystems and position them in the airframe. Consequently, the methods are integrated into the conceptual aircraft design process to enable multidisciplinary design with supporting domains. The methods are aimed to aid the design of conventional systems architectures and More Electric Aircraft (MEA) systems architectures as well. With these methodologies, the Systems Model Generator (SMG) application is developed in Python to facilitate semi-automatic wing subsystems sizing and orientation in the airframe based on top-level aircraft requirements, initial aircraft design parameters and system specific parameters. The subsystem models generated with the proposed methodology for short-medium range civil transport aircraft are verified and validated as well. Knowledge based systems and subsystems selection are implemented to facilitate semi-automated systems, subsystems and architecture selection, based on the aircraft configuration and systems specific requirements. Methods for automatic iterative fuel tanks sizing and intersection detection are implemented to further reduce the overall design time and make the tool more suitable for integrated sizing.With the multidisciplinary design framework, the conceptual parametric models, volume, mass, power consumption and position of the subsystems in the airframe are generated and propagated in the conceptual aircraft design stage; thus bridging the conceptual and the preliminary design stages. In the proposed framework, the domains of aircraft design generation, systems selection and sizing, subsystems selection and sizing, engine sizing and mission simulation are considered for the multidisciplinary design process. The domains are integrated with the DLR CPACS-RCE framework. A case study to demonstrate the process of integrated parametric subsystems sizing of the aircraft, with the proposed framework is presented. The aim of this case study is to assess the influence of the MEA systems architecture relative to the conventional systems architecture for a short-medium range transport aircraft, similar to the Airbus A320-200. In this case study, the quantitative influence of the subsystems' parameters on the aircraft design and performance parameters is determined and analysed. The subsystems' parameters constitute the mass, power consumption, volume and location of the subsystems in the airframe and the aircraft design parameters constitute the aircraft masses such as the overall empty mass and the fuel mass for the mission. The generation and propagation of the design and performance parameters of the aircraft through each domain of the framework are presented and analysed as well with the case study. In this case study, it is observed that the MEA systems architecture results in a lower mission fuel mass relative to the conventional systems architecture by nearly 2.3\%. Furthermore, these results are compared with literature and observed to be in the similar range of 2-7\%. Thus, the validated aircraft design framework presented in this thesis enables to substantially increases and propagate the design knowledge of aircraft systems, in the early design stages.AGILEAerospace Engineerin
COMPETITIVE RISK MANAGEMENT OF SERVICES IN HANDICRAFTS BUSINESS, NEPAL: SK HANDICRAFTS
No full textThe main motive of this thesis was to identify the competitive risk and the approaches to manage those risk. The case company for the thesis is SK handicrafts which is located at Thamel, Kathmandu, Nepal. As my case company is a type of small scale industry. The author is targeting the difficulties which the company will suffer when they will import and export their handicrafts products in the developing country like Nepal. Nepal is a small country located in the continent of Asia. It is surrounded by the two gigantic and developed countries like India and China. The ambition for the thesis is to jewel the competitive risk and the problems which the small-scale industries like SK handicrafts will face including its exporting of products especially to European market, competitors in Nepal.
The research on competitive risk management was conducted based on handicraft business in Nepal. The case company is SK handicraft exports. Not only for the thesis the author is much interested to do his own business in near future so the main reason behind my research is my dedication towards entrepreneurship. The author has made the thesis so simple that it is not hard for other to understand. The author has described about the indication and examine the risk things that may occur at any time and any situation. So, regarding what are the pre-cure for removing such risk from the company so where the company can achieve the further goals. I am doing research how does SK handicrafts products will increase in the local and foreign level; how can we support the small-scale enterprise like SK handicrafts to grow bigger in Asian and European market and what are its competitive management methods to do their business run properly. The author had made a clear view of first the description what actual my table of contents is then after in the second paragraph I have described how the description are interrelated to my case company SK handicrafts
American Sign Language (ASL) Fingerspelling dataset for Myo Sensor
No full textThis is the dataset used in the following publication. Please cite this publication if use this dataset:
This work was published on the 2017 ACM IUI .
@inproceedings{paudyal2016sceptre,
title={Sceptre: a pervasive, non-invasive, and programmable gesture recognition technology},
author={Paudyal, Prajwal and Banerjee, Ayan and Gupta, Sandeep KS},
booktitle={Proceedings of the 21st International Conference on Intelligent User Interfaces},
pages={282--293},
year={2016},
organization={ACM}
}
@inproceedings{paudyal2017dyfav,
title={Dyfav: Dynamic feature selection and voting for real-time recognition of fingerspelled alphabet using wearables},
author={Paudyal, Prajwal and Lee, Junghyo and Banerjee, Ayan and Gupta, Sandeep KS},
booktitle={Proceedings of the 22nd International Conference on Intelligent User Interfaces},
pages={457--467},
year={2017},
organization={ACM}
}
9 users wore the Myo Armband and data was collected for 5s. for each letter of the alphabet. The first 8 columns contain data for the 8 EMG pods, the next 3 are for Accelerometer, the next 3 are for Gyroscope and the final 3are for Orientation (Roll, Pitch and Yaw
An agent-based modelling and simulation framework to support strategic cargo airlift evaluation
No full textWhen there is a need to move cargo across the world in the fastest possible manner, airlift is the prime solution. Due to the potential extreme requirements of airlift, aircraft have to be capable of performing in a myriad of operational environments. To support future aircraft design loops, this work proposes a framework which couples aircraft design and operational effectiveness in an agent-based simulation, allowing a more direct evaluation of design choices. Aircraft are modelled with inputs akin to typical design tool outputs, and airlift operational objectives and events are parameterized to allow for user customization and mission tailoring. To deal with stochastic and unexpected events that occur within airlifts, such as aircraft servicing, cargo demand reformulation and airbase access restriction, the aircraft and cargo are modelled as agents and managed by a dispatcher. Aircraft bid for cargo with flights which are configured by the dispatcher, allowing cargo to choose its flight path according to the airlift objective. Through analyzing a theoretical disaster relief mission, the impact of disruptive events on airlift time, cost and cargo throughput is shown to be significant, motivating their inclusion in future analysis. An exploration of aircraft design and airlift objectives is also analyzed, which highlighted the variance in airlift performance due to changes in aircraft payload-range and operational logics. The results demonstrate the framework's ability to capture the varying complexities of the airlift system, exemplifying its utility in future airlift and aircraft design optimization and resilience testing.Aerospace Engineerin
Performance Evaluation of Object Proposal Generators for Salient Object Detection
No full textabstract: The detection and segmentation of objects appearing in a natural scene, often referred to as Object Detection, has gained a lot of interest in the computer vision field. Although most existing object detectors aim to detect all the objects in a given scene, it is important to evaluate whether these methods are capable of detecting the salient objects in the scene when constraining the number of proposals that can be generated due to constraints on timing or computations during execution. Salient objects are objects that tend to be more fixated by human subjects. The detection of salient objects is important in applications such as image collection browsing, image display on small devices, and perceptual compression.
This thesis proposes a novel evaluation framework that analyses the performance of popular existing object proposal generators in detecting the most salient objects. This work also shows that, by incorporating saliency constraints, the number of generated object proposals and thus the computational cost can be decreased significantly for a target true positive detection rate (TPR).
As part of the proposed framework, salient ground-truth masks are generated from the given original ground-truth masks for a given dataset. Given an object detection dataset, this work constructs salient object location ground-truth data, referred to here as salient ground-truth data for short, that only denotes the locations of salient objects. This is obtained by first computing a saliency map for the input image and then using it to assign a saliency score to each object in the image. Objects whose saliency scores are sufficiently high are referred to as salient objects. The detection rates are analyzed for existing object proposal generators with respect to the original ground-truth masks and the generated salient ground-truth masks.
As part of this work, a salient object detection database with salient ground-truth masks was constructed from the PASCAL VOC 2007 dataset. Not only does this dataset aid in analyzing the performance of existing object detectors for salient object detection, but it also helps in the development of new object detection methods and evaluating their performance in terms of successful detection of salient objects.Dissertation/ThesisMasters Thesis Electrical Engineering 201
Unveiling the Physicochemical Properties, Mineral Profile and Hemo-Protective Potential of Acacia Suma
No full textAnemia is condition when haemoglobin (Hgb) level is <13.0gm/dL in men and <12.0gm/dL in female. In women blood disorders like anemia, menstruation problems, miscarriage, fetus death, ischemia and stroke all are life threatening problems. The Acacia suma has been reported in Ayurvedic Pharmacopeia of India for traditional role in treatment of blood disorders. The hydroalcoholic extract yield was 9.75% and shown presence of phenols, flavonoides and tannins. The hemolytic assay and osmotic fragility assay were performed and percent hemolysis was analysed as Mean ± SD. Further, mineral content of the extract was determined using flame Atomic Absorption Spectrometry. In phytochemical screening the hydroalcoholic extract of Acacia suma shown presence of carbohydrate, proteins, amino acid, steroids, saponin, flavonoids, alkaloids, tannins and phenols. At concentration 250µl/ml, 150µl/ml and 50µl/ml the extract revealed 24.53 ± 3.92 %, 30.63 ± 4.18 % and 54.66 ± 8.92 percent hemolysis respectively. In mineral calcium was found highest among the elements (390.58 ± 7.39 ppm) followed by zinc (26.488 ± 0.32 ppm) and iron (25.84 ± 0.79 ppm). As concentration increases, extract exhibited significant hemo-protective potential and it could be an effective medicine for the treatment of iron deficiency anemia and hemolytic anemia
