745 research outputs found
Design Development and CFD Simulation of a Variable Twist Wing
No full textWing twist is an aerodynamic feature added to aircraft wings to adjust lift distribution along the wing. Often, the purpose of lift redistribution is to ensure that load distribution is uniform from wing tip to root, it ensures that the effective angle of attack is always lower at the wing tip than at the root, meaning the root will stall before the tip. This is desirable because the aircraft's flight control surfaces are often located at the wingtip, and the variable stall characteristics of a twisted wing alert the pilot to the advancing stall while still allowing the control surfaces to remain effective, meaning the pilot can usually prevent the aircraft from stalling fully before control is completely lost. Twist that decreases the local chord's incidence from root to tip is sometimes referred to as washout. In this project the design is done in GAMBIT software, and CFD simulation of twisted wing is done in fluent software, the designed model is tested in software at different twist angles, and at different angles of attack to find the aerodynamic properties like CD, CL, and pressure
Determination of Fatigue Life of Surface Propeller by Using Finite Element Analysis
No full textPropeller design aims at achieving high propulsive efficiency at low levels of vibration and noise, usually with minimum cavitations. Achieving this aim is difficult with conventional propellers, as ships have become larger and faster propeller diameters have remained limited by draught and other factors. Surface piercing propeller offers an attractive alternative to high-speed crafts, which operate under limited draught. The performance of the vehicle depends upon the efficiency of the propeller. The geometric shape and its surface finish will decide the efficiency of the propeller. The material used is carbon UD and aluminum. The present project basically deals with the modeling, Analysis of the propeller using composite material of a marine vehicle having low draft. A propeller is complex 3D model geometry. CATIA modeling software is used for generating the blade model and tool path on the computer. Sectional data, pitch angle of the propeller are the inputs for the development of propeller model. Finite element analysis was carried out using ABAQUS. The propeller model developed in CATIA is converted in to IGES file and then imported to HYPERMESH for developing fine mesh of the model. As a part of the analysis static structural testing was conducted by varying material properties in pre-processing stage. Further fatigue analysis was performed to analyze the factor of safety. Based on the results obtained from both static analysis and dynamic analysis a better performing material is identified for the development of a propeller. The post processed results obtained from both analysis methods recommends carbon UD/ Epoxy for the fabrication of propeller
Factorization of isometries of hyperbolic 4-space and a discreteness condition:
No full textGilman's NSDC condition is a sufficient condition for the discreteness of a two generator subgroup of PSL(2,C). We address the question of the extension of this condition to subgroups of isometries of hyperbolic 4-space. While making this new construction, namely the NSDS condition, we are led to ask whether every orientation preserving isometry of hyperbolic 4-space can be factored into the product of two half-turns. We use some techniques developed by Wilker to first, define a half-turn suitably in dimension 4 and then answer the former question. It turns out that defining a half-turn in this way in any dimension n enables us to generalize some of Gilman's theorems to dimension greater than or equal to 4. We also give an exposition on part of Wilker's work and give new proofs for some of his results.Ph.D.Includes bibliographical references (p. 52-53)by Karan Mohan Pur
Bibliographics for the 983 eprints in the live archives of E-LIS : trends and status report up to 7th July 2004, based on author-self-archiving metadata
No full textThe priority for ideas and philosophy related to "Network Theory" have been traced back and documented by Braun(2004),and credit goes to Karinthy(1929).The IT has empowered to realise it, as the most practical phenomena and it is no more a humour. The OAI (Open Archives Initiatives)and ACIS (Academic Contributor Information System)are progressive in the direction ,which may lead to realise the "Collective Genius" at global level. Focus of present study is on Author-Self-Archiving (A-S-A)Metadata of the 983 Eprints in the Live Archives of the E-LIS (EPrints of Library and Information Science),which were approved till 7th July 2004.The A-S-A Metadata was used for librametric analysis. Self-explanatory bibliographics are illustrated.The highlights include: Conference papers (34%); highest approval, June 2004 (28%); published archives (76%);not refereed (52%); not in public domain (60%); highest self-archiving-author (De Robbio, Antonella).The Nos. of EPrints having single JITA domain specifications were: Theoretical and general aspects of libraries and information(27); Information use and sociology of information(80);Users,literacy and reading(13);Libraries as physical collections(30);Publishing and legal issues(57);Management(13);Industry, profession and education(36);Information sources, supports, channels(113) ; Information treatment for information services, Information functions and techniques (101); Technical services libraries, archives and museums(25); Housing technologies(1); Information technology and library technology(92); and Inter-domainery (395) i.e. having specifications of two or more than two JITA classes
Designing a successful library school field experience
No full textTo share the library school field experience paradigm that the authors developed after their successful participation as a supervisor and student.
Design/methodology/approach – A review of field experience literature is provided. The field experience paradigms and perspectives pertaining to the supervisor and the student are explained. The paradigm is suggested as a model for field experience participants and their supervisors.
Findings – The field experience paradigm for the supervisors elucidates the stages – planning, training, mentoring and evaluation. The paradigm for students explains the phases – awareness, interests, planning and participation.
Research limitations/implications – The focus of the field experience, from which the paradigm emanated, was to train and prepare the student for agricultural librarianship in an academic library. The application of the paradigm may vary for different situations.
Practical implications – The paradigm is expected to be useful for supervisors and students of field experience programs.
Originality/value – This paradigm stems from the participation of the authors as a field experience supervisor and student. The steps and methods the authors followed will help advance future field experience programs
Rethinking web platform extensibility
No full textThe modern Web platform provides an extensible architecture that lets third party extensions, often untrusted, enhance and customize the Web browser and the Web applications. While the prevalence of extensions for both browsers and applications has been instrumental in making the Web browser hugely successful, there are two critical issues that the designers of the modern Web platform have not yet tackled in a principled manner. First, both the third party extensions and the extensible components of the Web platform include numerous vulnerabilities, which can compromise the security and privacy of end users. Second, the black-box and opaque nature of the Web platform limits the extent of extensibility achievable for Web developers, thereby hampering the development of novel browser-based user applications. This dissertation develops new tools and techniques to address the problem of insecure extensibility in the Web platform, proposes novel language and system level solutions to make extensibility a first class primitive for developing Web software, and demonstrates that these methods are applicable to real-world Web applications and Web browser extensions. Specifically, this dissertation makes the following three contributions. First, it studies and characterizes the problem of insecure JavaScript-based Web browser extensions using a specialized program analysis system, Sabre, which leverages JavaScript-level information flow mechanism to detect violations in client’s confidentiality and integrity arising from execution of untrusted extensions. Second, it formalizes the concept of transactions for JavaScript and implements Transcript, a language runtime system that allows hosting principals, i.e., Web browser and Web applications, to isolate untrusted JavaScript-based extensions using speculative execution. Lastly, this dissertation presents the design and implementation of Atlantis, a novel, extensible browser architecture that allows Web applications to define their own runtime environment and become more secure and robust. Atlantis enables developers with primitives to manage the Web application’s security and privacy, and removes their dependence on opaque, legacy Web interfaces.Ph. D.Includes bibliographical referencesby Mohan Dhawa
INSPEC database analysis for Knowledge Management records
No full textThe study deals with the Knowledge Management papers covered in the INSPEC, an international database on Information Science, Physical Sciences, Engineering and Computer Sciences. The papers have been analysed in terms of their content and other scientometric parameters
Physically interpretable machine learning methods for transcription factor binding site identification using principled energy thresholds and occupancy:
No full textRegulation of gene expression is pivotal to cell behavior. It is achieved predominantly by transcription factor proteins binding to specific DNA sequences (sites) in gene promoters. Identification of these short, degenerate sites is therefore an important problem in biology. The major drawbacks of the probabilistic machine learning methods in vogue are the use of arbitrary thresholds and the lack of biophysical interpretations of statistical quantities. We have developed two machine learning methods and linked them to the biophysics of transcription factor binding by incorporating simple physical interactions. These methods estimate site binding energy, recognizing that it determines a site's function and evolutionary fitness. They use the occupancy probability of a transcription factor on a DNA sequence as the discriminant function because it has a straightforward physical interpretation, forms a bridge between binding energy and evolutionary fitness, and has a natural threshold for classifying sequences into sites that allows establishing the threshold in a principled manner. Our methods incorporate additional characteristics of sites to enhance their identification. The first method, based on a hidden Markov model (HMM), identifies self-overlapping sites by combining the effects of their alternative binding modes. It learns the threshold by training emission probabilities using unaligned sequences containing known sites and estimating transition probabilities to reflect site density in all promoters in a genome. While identifying sites, it adjusts parameters to model site density changing with the distance from the transcription start site. Moreover, it provides guidance for designing padding sequences in experiments involving self-overlapping sites. Our second method, the Phylogeny-based Quadratic Programming Method of Energy Matrix Estimation (PhyloQPMEME), integrates evolutionary conservation to reduce false positives while identifying sites. It learns the threshold by solving an iterative quadratic programming problem to optimize the distribution of correlated binding energies of neutrally evolving orthologous sequences while restricting the values of binding energies of known sites and their orthologs. We have used the NF-κB transcription factor family as a case study for both methods and gained new insights into its biology.Ph.D.Includes bibliographical references (p. 210-226)by Amar Mohan Drawi
Clustering based causal topic mining
No full textEvents in the world generate an enormous amount of textual data like tweets and news articles. These events also manifest in the form of changes to time-series numeric data. This thesis deals with the problem of extracting these events from the timestamped document collection in the form of topics that cause a change in a time-series. We develop a conceptual framework for that can be used to analyze different causal topic mining algorithms. We also propose two novel clustering based algorithms - cCTM-CF and cCTM-CoF to generate causal topics. We evaluate these algorithms both qualitatively, and quantitatively by comparing their coherence and correlation scores to that of the baseline generative causal topic model - gCTM. We found that cCTM-CoF performs 35% and 62.5% better according to these metrics as compared to the baseline.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-05-01The student, Vishaal Mohan, accepted the attached license on 2017-04-24 at 14:23.The student, Vishaal Mohan, submitted this Thesis for approval on 2017-04-24 at 14:28.This Thesis was approved for publication on 2017-04-25 at 11:02.DSpace SAF Submission Ingestion Package generated from Vireo submission #11014 on 2017-08-10 at 14:32:32Made available in DSpace on 2017-08-10T19:52:22Z (GMT). No. of bitstreams: 2
MOHAN-THESIS-2017.pdf: 386969 bytes, checksum: 59c2389baaf5254174bf10112078b1c6 (MD5)
LICENSE.txt: 4210 bytes, checksum: 87b6e69d56363c7d9b862972ab545b91 (MD5)
Previous issue date: 2017-04-25Embargo set by: Colleen Fallaw for item 102679
Lift date: 2019-08-10T21:25:30Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 102679 on 2019-08-11T09:15:39Z
Refinement of solutions to the linear complimentarity problem
No full textNash equilibrium;game theaory;matrices
- …
