21 research outputs found
Investigating MapReduce framework extensions for efficient processing of geographically scattered datasets
No full textWe observe two important trends brought about by the evolution of Internet in recent years. Firstly to improve end-to-end application performance in presence of bottlenecks in the wide-area Internet communication, modern day Internet services are designed in a decentralized fashion involving geographically distributed data-centers connected through the Internet. Secondly the pervasive nature of Internet services has resulted into an exponential growth in the size of digital information created, captured or replicated. Organizations are keenly interested in mining this information to uncover trends, statistics and other actionable information which can give them competitive advantage. These two trends necessitate the design of a large-scale data processing system which can operate efficiently in a distributed environment involving multiple datacenters connected through the Internet. In recent years, MapReduce programming model and specifically its open source implementation Hadoop is gaining a lot of traction for performing large-scale data processing in a centralized environment. Our evaluation of different real-world usage scenarios of Hadoop deployments revealed that the organizations with the distributed datasets are required to copy the entire dataset to a centralized location so that it can be efficiently processed by the Hadoop MapReduce framework. As the Internet evolves growth in the size of distributed datasets would outpace the improvements in the network bandwidth available in the Internet. At that point the approach of copying the entire dataset to a single location using Internet would become infeasible. In this thesis, we have investigated the possibility of extending the MapReduce and specifically Hadoop framework to operate in a distributed environment involving multiple datacenters connected through the Internet. We also have proposed policies to improve the performance of Hadoop MapReduce framework in a distributed environment. We have observed that our policies improve the performance of Hadoop framework substantially.M.S.Includes bibliographical referencesby Hrishikesh Gadr
Framework for crawling and local event detection using twitter data
No full textTwitter is a popular social media service, with millions of registered users as of December 2010. Twitter hosts substantial amounts of user-contributed data of real-world events. Twitter‟s core functions represent a simple social awareness stream model. Twitter users share information about upcoming events, the events the users are attending and events being broadcasted. The users also specify their location in their profile on Twitter. We can programmatically collect data from Twitter using their API and detect top terms and events in the data. Researchers can use this program to collect any kind of data from social networks easily. Journalists can get a real time the list of events detected by this method. In this thesis, we propose a solution to tackle the problem above. We wrote scripts that collected Twitter data through Twitter API. The scripts collect data according to user location and by search keywords. We built a web interface that provides mechanism to manage the collection of data. The web interface allows addition of new locations and keywords to the data collection. We collected Twitter data for important locations across the United States of America and the world using these tools. We use two approaches to detect trends in the data. In the first approach, we detected spikes in data by looking at overall rate of tweets at each location over a period of time. In the second approach, .we indexed the data according to location and time of the day. Then, we identified trends in the indexed data by ranking the terms according to spikes in term frequency. Using our framework, we can detect the top events and trends for a given time period and location according to Twitter data.M.S.Includes bibliographical referencesby Hrishikesh Baksh
Characterizing Spatio-temporal Dynamics of Land Use and Land Cover in Urban Environment of Chhatrapati Sambhajinagar, Maharashtra, India
No full textUrban areas in India are growing rapidly along with increase in industrial expansions and installation of modern infrastructural facilities which creates a demographical pressure and bring changes urban environment. The Land Use and Land Cover (LULC) are the parameters changes in due course of time and places. Therefore, LULC analysis is essential to know the developmental trends in urban areas through the change in land use patterns of Chhatrapati Sambhajinagar. In present study the Spatio-temporal LULC changes were analyzed in the study area by using GIS tools and techniques. Maximum likelihood supervised classification is used to produce LULC maps, backed by statistical and analytical methods of confusion matrix or error matrix to gain precise outcomes. The results revealed that, the land use land cover changed significantly from year 2011 to 2023 especially in built-up area in city area which was increased by 1.6% and agricultural land decreased by 6.8%. There was a significant increase of 8.7% in barren land in and around city area and tree cover has been dropped by 3.6%. Overall accuracy of the error matrix is 83% and 90% respectively. The downslide of agricultural land and tree cover is the result of an upswing of urbanization and confirming degradation of natural vegetation in study area
Structural and optical behavior of thin films of protein (BSA)-Polyelectrolyte (PAA, PSS) complexes
No full textNumerical Study On The Impact Of Self Induced Gravity Waves On Offshore Wind Farms
No full textThe present work studies the impact of self-induced Atmospheric Gravity Waves (AGWs) excited by an moderately sized offshore wind farm immersed in a Conventionally Neutral Boundary Layer (CNBL). A wind farm of finite span-wise length, consisting of 25 NREL 15MW wind turbines laid out in (5 X 5 Aligned manner) is considered. In order to achieve the same, two customized open source CFD RANS solvers are used, based on the OpenFOAM and SOWFA environments. The study primarily focuses on the impact of thermal stratification in the Free Atmosphere, the strength of the capping inversion and height of the same on the characteristics of the AGWs excited. Further, the work also evaluates the impact of the excited AGWs on the wind farm in the form of velocity deficits at each individual turbine column and also power down the analysis.The study finds that for a higher capping inversion strength, the AGWs excited by the wind farms are trapped and propagate horizontally along the capping inversion along with its vertically propagating counterpart. These cause velocity fluctuations at the hub height of the turbine, which results in AGW induced wind farm blockage that lowers the amount of incoming kinetic energy at the first turbine row and an increased velocity at the last two rows. Furthermore, the trapped AGWs cause the collective wake of the wind farm to recover faster. Moreover, the study proves that the height of the capping inversion determines the extent of AGW excitation by the wind farm. It was found lower capping inversion heights led to a higher AGW excitation and higher AGW induced flow blockage and wake recovery. Lastly, the study also finds that the thermal stratification in the Free Atmosphere determines the vertical wavelength of the AGWs propagating in the free atmosphere. Furthermore, the study also reports that for a higher Free Atmosphere stratification, a lower AGW induced blockage is observed.Aerospace Engineerin
Balanced-force numerical method for two phase flow at the onset of instability
No full textThe Interface Capturing method, which is a finite volume method as formulated by Queutey and Vissoneau for free surface immiscible, incompressible multiphase flows employs a collocated arrangement of unknownsand achieves a discrete force balance for the case when the interface coincides with the faces of the control volumes in the computational domain. This constraint limits the applicability of the method. Furthermore,the authors do not provide the exact formulation of the operators involved in the pressure velocity coupling. In the present research, a balanced-force numerical method is formulated, applicable for an interface thatneither has to coincide nor be aligned with the faces of the control volumes. The approach consists of the reconstruction of the values of the flow variables at the interface based on the interface jump conditions, with which the limit values of the normal derivatives at the interface are calculated. Furthermore, the construction of the operators of the discrete system is delineated to achieve a discrete force balance, by incorporating the reconstructed flow variables and employing a discretization which complies with the interface jump conditions. It is sufficient for a stationary discrete formulation to comply with the differential equation and the interface jump conditions. However, to apply this approach to solve unsteady flow problems the influence of the reformulated operators on the stability properties of the system should also be investigated.The properties of the individual operators are analyzed as well as their behaviour when they are embedded in the complete solver algorithm. Results are shown for both steady and unsteady test cases and compared with numerical results obtained with OpenFOAM. The resulting framework avoids the occurrence ofspurious velocities as it discretely complies with the interface conditions.<br/
Kernel Regression Coefficients for Practical Significance
No full textQuantitative researchers often use Student’s t-test (and its p-values) to claim that a particular regressor is important (statistically significantly) for explaining the variation in a response variable. A study is subject to the p-hacking problem when its author relies too much on formal statistical significance while ignoring the size of what is at stake. We suggest reporting estimates using nonlinear kernel regressions and the standardization of all variables to avoid p-hacking. We are filling an essential gap in the literature because p-hacking-related papers do not even mention kernel regressions or standardization. Although our methods have general applicability in all sciences, our illustrations refer to risk management for a cross-section of firms and financial management in macroeconomic time series. We estimate nonlinear, nonparametric kernel regressions for both examples to illustrate the computation of scale-free generalized partial correlation coefficients (GPCCs). We suggest supplementing the usual p-values by “practical significance” revealed by scale-free GPCCs. We show that GPCCs also yield new pseudo regression coefficients to measure each regressor’s relative (nonlinear) contribution in a kernel regression
Direct osmosis for the concentration of bromelain from pineapple
No full textThis Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page
Rare-earth oxides in aluminoborosilicate glasses and their impact on molybdenum oxide solubility in nuclear waste glasses
No full textThe United States department of energy (DOE) has proposed an alkali alkaline-earth aluminoborosilicate-based glass-ceramic to immobilize the projected high-level waste (HLW) generated from reprocessing of its spent civilian nuclear fuel. The glass-ceramic is expected to improve molybdenum oxide (MoO₃) retention, which otherwise suffers from poor solubility in borosilicate-based glasses typically used for HLW immobilization in several countries. Irrespective of the waste form chosen, a fundamental understanding of the compositional and structural drivers governing MoO₃ solubility in borosilicate/aluminoborosilicate glasses is desired to design advanced waste forms with higher loading capacities. The literature in this regard reports several studies, yet several open questions need to be addressed. This work addresses two open questions regarding MoO₃ solubility: (i) What are the solubility and retention limits of MoO₃ in aluminoborosilicate glasses as a function of glass chemistry? (ii) Why does MoO₃ exhibit significantly higher solubility with the incorporation of rare-earth oxides (RE₂O₃) in aluminoborosilicate glasses?
A systematic study conducted on a series of model HLW glasses reveals that MoO₃ solubility improves by 2x from 1.5 mol% to 3 mol% when RE₂O₃ (RE = Nd) is added to a Na₂O-CaO-Al₂O₃-B₂O₃-SiO₂ glass. The results, when analyzed in the context of past literature, reveal that (i) RE₂O₃ phase separates a homogenous aluminoborosilicate-based glass into borate-rich, and aluminosilicate-rich regions and preferentially enters the borate-rich region; (ii) the excess RE³⁺ clusters in the aluminosilicate-rich region and (iii) molybdenum enters the RE-borate-rich region as the molybdate oxyanion (MoO₄²⁻) forming a stable Mo-RE-B-O glass phase which suppresses crystallization of alkali/alkaline-earth molybdates and improves MoO₃ solubility. The above hypothesis is further explored by investigating the partitioning and clustering behavior of RE³⁺ (RE = Nd/La) in a peralkaline aluminoborosilicate glass doped with varying concentrations of RE₂O₃ (0.001 to 5 mol%). In these glasses, free induction decay (FID)-detected electron paramagnetic resonance (EPR) reveals that RE³⁺ co-exists as EPR-detectable – isolated RE³⁺ centers & dipole-coupled RE clusters, and EPR-undetectable exchange-coupled RE clusters, with higher RE₂O₃ concentrations further promoting RE³⁺ clustering. The environment of the EPR-detectable RE as investigated by electron spin echo envelope modulation (ESEEM) spectroscopy reveals an alkali/silica-rich environment for the isolated RE³⁺ centers and an alkali/boron/silica-rich environment for the dipole-coupled RE clusters. The EPR-undetectable RE clusters are predicted to exist in alkali/boron-rich nano-scale regions, depleting the leftover glass of the same elements. Based on these findings, a study is eventually performed to investigate further the role of RE³⁺ in improving the solubility of MoO₃ in alkali alkaline-earth aluminoborosilicate-based model high-level waste glasses. It is thus hypothesized that MoO₃ preferentially enters the alkali/boron-rich environment of the exchanged-coupled RE clusters where the molybdate oxyanion (MoO₄²⁻) achieves its charge neutrality primarily from RE³⁺ than alkali ions, thereby suppressing the crystallization of the alkali molybdate phase and improving MoO₃ solubility.
A subsidiary study investigating the impact of ruthenium oxide (RuO₂) – one of the components of HLW, on the crystallization behavior and electrical conductivity of MoO₃-containing nuclear waste glasses is also presented. RuO₂ in these glasses is found to exhibit very low solubility (460 parts per million by weight), and above the solubility limit is observed to precipitate into polyhedral/needle-shaped RuO₂ crystals, which impart metal-like conductivity in the investigated glasses.Ph.D.Includes bibliographical reference
