153 research outputs found
sj-docx-1-pie-10.1177_09544089221150731 - Supplemental material for Investigation of mechanical behavior of graphene nanoplatelets and carbon fiber-reinforced hybrid laminate composites under different environment aging conditions
No full textSupplemental material, sj-docx-1-pie-10.1177_09544089221150731 for Investigation of mechanical behavior of graphene nanoplatelets and carbon fiber-reinforced hybrid laminate composites under different environment aging conditions by Anurag Namdev, Amit Telang and Rajesh Purohit in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
sj-docx-2-pie-10.1177_09544089221150731 - Supplemental material for Investigation of mechanical behavior of graphene nanoplatelets and carbon fiber-reinforced hybrid laminate composites under different environment aging conditions
No full textSupplemental material, sj-docx-2-pie-10.1177_09544089221150731 for Investigation of mechanical behavior of graphene nanoplatelets and carbon fiber-reinforced hybrid laminate composites under different environment aging conditions by Anurag Namdev, Amit Telang and Rajesh Purohit in Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering</p
Development of a computational tool for forensic DNA analysis
No full textForensic DNA analysis consists of a DNA profiling process by a method called as STR Analysis, short for Short Tandem Repeats. By using the statistics it provides, various probabilistic approaches are implemented in a software package to find out DNA profile matches and individual identifications. This study has contributed in the design, development and integration of an easy to use and interactive software application to find the number of contributors in a DNA sample and to find a match against it with another person’s DNA. This research specifically deals with the (1) design of an algorithm for filtering unfiltered DNA profile samples to remove bleed-through peaks; (2) design of an interactive interface for MatchIt, where a DNA sample of a person of interest is tested against a DNA sample to find a match; and (3) data modeling, design and integration of a database for the software.M.S.Includes bibliographical referencesby Anurag Arnol
Design of a morphing airfoil exhibiting bi-stability using topology optimization
Get PDFThis study aims to harness the geometric non-linearity of structures to design a novel camber morphing mechanism for a bi-stable airfoil using topology optimization. The goal is to use snap-through instabilities to actuate and maintain the shape of the morphing airfoil. Topology optimization has been used to distribute material over the design domain and to tailor the nonlinear response of the baseline structure to achieve the desired bi-stable behavior. The large scale deformation undergone by the structure is modeled using a hyperelastic material model. The non-linear structural equilibrium equations are solved using arc-length and displacement-controlled Newton-Raphson analysis. Isoparamteric finite element evaluation is used for analyzing kinematic and deformation characteristics of the structure. The optimization problem is solved using a computationally efficient nonlinear optimization algorithm, the Method of Moving Asymptotes (MMA), with a Solid Isoparametric Material Penalization (SIMP) scheme. The gradient information required for the optimization has been evaluated using an adjoint sensitivity formulation. Two different design domains, one with a structured quadrilateral mesh and another with an unstructured triangular mesh, are investigated and compared. The effect of different optimization parameters on the final optimized structure and its behaviour has also been analyzed. The final result is a novel camber morphing mechanism without the disadvantages of increased weight and higher maintenance costs associated with conventional actuation mechanisms. The optimized results obtained numerically are then 3-D printed to evaluate their performance characteristics.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-05-01The student, Anurag Bhattacharyya, accepted the attached license on 2017-04-21 at 10:08.The student, Anurag Bhattacharyya, submitted this Thesis for approval on 2017-04-21 at 10:28.This Thesis was approved for publication on 2017-04-24 at 17:31.DSpace SAF Submission Ingestion Package generated from Vireo submission #10960 on 2017-08-10 at 15:06:45Made available in DSpace on 2017-08-10T20:33:19Z (GMT). No. of bitstreams: 3
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Techniques to improve dynamic cache management with static data classification
No full textThesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 55-59).Cache hierarchies are increasingly non-uniform and difficult to manage. Several techniques, such as scratchpads or reuse hints, use static information about how programs access data to manage the memory hierarchy. Static techniques are effective on regular programs, but because they set fixed policies, they are vulnerable to changes in program behavior or available cache space. Instead, most systems rely on dynamic caching policies that adapt to observed program behavior. Unfortunately, dynamic policies spend significant resources trying to learn how programs use memory, and yet they often perform worse than a static policy. This thesis presents Whirlpool, a novel approach that combines static information with dynamic policies to reap the benefits of each. Whirlpool statically classifies data into pools based on how the program uses memory. Whirlpool then uses dynamic policies to tune the cache to each pool. Hence, rather than setting policies statically, Whirlpool uses static analysis to guide dynamic policies. Whirlpool provides both an API that lets programmers specify pools manually and a profiling tool that discovers pools automatically in unmodified binaries. On a state-of-the-art NUCA cache, Whirlpool significantly outperforms prior approaches: on sequential programs, Whirlpool improves performance by up to 38% and reduces data movement energy by up to 53%; on parallel programs, Whirlpool improves performance by up to 67% and reduces data movement energy by up to 2.6x.by Anurag Mukkara.S.M
Critical Components Identification for Cyber-Physical Power Systems Considering Time-Varying Operational States
No full textThe security issues of Cyber-Physical power Systems (CPS) have attracted widespread attention from scholars. Vulnerability assessment emerges as an effective method to identify the critical components and thus increase the system resilience. While efforts have been made to study the vulnerability features of power systems under the occurrence of a single, discrete disturbance or failure at a specific time instant, this paper focuses on identifying the critical components of the cyber-physical system considering time-varying operational states. To investigate the potentially ever-changing CPS vulnerability features, in this paper we construct a database of cascading failure chains using quasi-dynamic simulations to capture the vulnerability relationships among components under time-varying operational states. Then, by adopting sequential mining algorithms, we mine the most frequent cascading failure patterns and identify the critical components based on the data mining results. Simulation studies are conducted on IEEE 39-bus and IEEE RTS-96 systems to evaluate the effectiveness of the proposed method for the identification of critical components at both cyber and physical layers. Intelligent Electrical Power GridsElectrical Sustainable Energ
Hierarchical design of morphing shape-memory polymer structures via topology optimization
Get PDFShape memory polymers (SMPs) are a class of active polymeric materials that have the ability to regain their original undeformed configuration from a deformed state under the application of an external stimulus. In this study, we focused on the design optimization of SMPs that are actuated by the application of a thermal gradient.
This study puts forward an optimization framework for systematic design of shape morphing structures capable of exhibiting large deformations with SMPs. A hierarchical two-stage design procedure is adopted. In the first stage, basic unit structures including a twisting structure and a bending structure are designed using a topology optimization framework. A finite-element analysis incorporating the additive decomposition of small strains, is implemented to analyze and predict temperature-dependent displacement response of SMPs. The finite element method consists of a viscoelastic material model combined with a temperature-dependent strain storage mechanism, giving SMPs their characteristic property. The thermo-mechanical characteristics of SMPs are exploited to actuate structural deflection to enable morphing toward a target shape. A time-dependent adjoint sensitivity formulation implemented through a recursive algorithm is used to calculate the gradients required for the topology optimization algorithm. Multimaterial topology optimization combined with the thermo-mechanical programming cycle is used to optimally distribute the active and passive SMP materials within the design domain. This allows us to tailor the response of the structures to design them with specific target displacements, by exploiting the difference in the glass-transition temperatures of the two SMP materials. Forward analysis and sensitivity calculations are combined in an PETSc-based optimization framework to enable efficient multi-functional, multimaterial structural design with controlled deformations.
In stage II of the design process, the basic twisting and bending structures are fabricated and their kinematic characteristics are validated using a 4D printing technique. The main goal of this design stage is to use these basic twisting and bending structures to computationally design a self-tying knot. A forward kinematics framework is implemented using these bending and twisting angles as input and the optimal sequence of the basic twisting and bending structures along a morphable kinematic chain are generated by using a genetic algorithm with a predetermined ideal knot chosen as the target shape. The optimal sequence is then 3D printed and subjected to the thermo-mechanical programming cycle to compare the kinematic characteristics of the computationally designed structure with the mathematical knot. The results obtained show good agreement between the ideal knot and the computational design.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-08-01The student, Anurag Bhattacharyya, accepted the attached license on 2021-07-14 at 13:31.The student, Anurag Bhattacharyya, submitted this Dissertation for approval on 2021-07-14 at 14:59.This Dissertation was approved for publication on 2021-07-15 at 10:51.DSpace SAF Submission Ingestion Package generated from Vireo submission #16935 on 2022-01-12 at 13:04:57Made available in DSpace on 2022-01-12T22:56:09Z (GMT). No. of bitstreams: 2
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Episode 026: The Long Road to Mexico
No full textHow does a tiny insect migrate thousands of miles from Canada to Mexico each year? What does the decline of monarch butterflies tell us about the ecological health of our continent? How are scientists using gene editing to understand how insects have evolved to tolerate poisonous plants?
Anurag Agrawal is a biologist at Cornell University who studies plant-insect interactions, including monarch butterflies. He is the author of a new book called Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution. On this episode, Art and Marty talk with Anurag about the incredible migration of the monarch butterfly, the recent decline in population and a fascinating study where scientists edited the genomes of fruit flies to make them resistant to a poisonous plant that monarchs eat.https://scholarworks.umt.edu/bigbiology_podcasts/1026/thumbnail.jp
Message from the chairs
No full text"Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public."Intelligent Electrical Power Grid
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