Categories
Jobs/Internships

Postdoctoral Research Associate – Machine Learning for Complex System Prognostics

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Date: Oct 8, 2020

Location: Oak Ridge, TN, US, 37830

Company: Oak Ridge National Laboratory

Requisition Id 4156 

Overview: 

The Neutron Sciences Directorate (NScD) at Oak Ridge National Laboratory (ORNL) operates the High Flux Isotope Reactor (HFIR), the United States’ highest flux reactor based neutron source, and the Spallation Neutron Source (SNS), the world’s most intense pulsed accelerator based neutron source. Together these facilities operate 30 instruments for neutron scattering research, each year carrying out in excess of 1,000 experiments in the physical, chemical, materials, biological and medical sciences. HFIR also provides unique facilities for isotope production and neutron irradiation. To learn more about Neutron Sciences at ORNL go to: http://neutrons.ornl.gov. Oak Ridge National Laboratory is also a leader in computational and computer science, with unique strengths in high-performance computing and data analytics with applications to the physical and biological sciences. 

We are seeking a postdoctoral research associate who will focus on signal processing, statistical analysis, probabilistic theory and machine learning with emphasis on diagnostics and prognostics applications. This position resides in the Accelerator Science and Technology Section in the Research Accelerator Division, Neutron Sciences Diretorate at Oak Ridge National Laboratory (ORNL).  

As part of our research team, you will work with accelerator and target systems specialists and machine learning experts to develop, integrate and apply machine learning methods to improve performance of the SNS 1.4 MW accelerator and target systems.

Major Duties/Responsibilities: 

  • Develop, implement and apply new machine-learning (ML) and statistical methods techniques to sensor and component health monitoring, anomaly detection and fault isolation
  • Develop and apply both first-principles-based and data-driven techniques to solving complex engineering problems
  • Perform uncertainty quantification and uncertainty propagation analyses

Basic Qualifications:

  • PhD in nuclear, electrical engineering, mechanical, computer engineering, or engineering physics, computational science or a related field within the past 5 years.
  • Experience with open-source machine-learning tools, such as TensorFlow, pyTorch or Keras

Preferred Qualifications:

  • Experience with applying and deploying recent machine-learning methods for solving complex engineering problems, including diagnostics and prognostics of complex engineered systems
  • Experience in physics-informed machine learning for analysis of physical systems
  • Experience with uncertainty quantification methods and application of those methods in complex systems
  • Experience working in Linux environments on large high-performance cluster computing architectures
  • Demonstrated experience in statistical methods and machine-learning methods, with a specific application to time-series datasets from multiple sensors
  • Strong understanding of underlying mathematics of signal processing, filtering and machine learning to unfold unique signatures in typical noisy time-series data
  • Demonstrated results-oriented problem-solving skills, and a willingness to apply those skills to a variety of engineering problems
  • Excellent communication skills (verbal, presentation and scientific writing) that enable effective interaction with technical peers, program managers, and sponsors
  • Strong scholarly and publication record that demonstrates independence and initiative taking
  • Ability to work independently and in a team environment, thoroughly document work performed

Additional Information:

Applicants cannot have received their Ph.D. more than five years prior to the date of application and must complete all degree requirements before starting their appointment. The appointment length will be up to 24 months with the potential for extension. Initial appointments and extensions are subject to performance and availability of funding.

This position will remain open for a minimum of 5 days after which it will close when a qualified candidate is identified and/or hired.

We accept Word (.doc, .docx), Adobe (unsecured .pdf), Rich Text Format (.rtf), and HTML (.htm, .html) up to 5MB in size. Resumes from third party vendors will not be accepted; these resumes will be deleted and the candidates submitted will not be considered for employment.
If you have trouble applying for a position, please email ORNLRecruiting@ornl.gov.


ORNL is an equal opportunity employer. All qualified applicants, including individuals with disabilities and protected veterans, are encouraged to apply.  UT-Battelle is an E-Verify employer.Apply now 

Categories
Defenses

Dissertation Defense: A COMPREHENSIVE EVALUATION OF FEATURE-BASED MALICIOUS WEBSITE DETECTION.”

Author: John McGahagan

Advisory Committee:
Professor Michel Cukier, Chair
Professor Jennifer Golbeck, Dean’s Representative
Associate Professor Katrina Groth
Professor Jeffrey Herrmann
Professor Mohammad Modarres 

Date/Time: October 23rd 1pm-3pm ET

Abstract: Although the internet enables many important functions of modern life, it is also a ground for nefarious activity by malicious actors and cybercriminals. For example, malicious websites facilitate phishing attacks, malware infections, data theft, and disruption. A major component of cybersecurity is to detect and mitigate attacks enabled by malicious websites. Although prior researchers have presented promising results – specifically in the use of website features to detect malicious websites – malicious website detection continues to pose major challenges. This dissertation presents an investigation into feature-based malicious website detection. We conducted six studies on malicious website detection, with a focus on discovering new features for malicious website detection, challenging assumptions of features from prior research, comparing the importance of the features for malicious website detection, building and evaluating detection models over various scenarios, and evaluating malicious website detection models across different datasets and over time. We evaluated this approach on various datasets, including: a dataset composed of several threats from industry; a dataset derived from the Alexa top one million domains and supplemented with open source threat intelligence information; and a dataset consisting of websites gathered repeatedly over time. Results led us to postulate that new, unstudied, features could be incorporated to improve malicious website detection models, since, in many cases, models built with new features outperformed models built from features used in prior research and did so with fewer features. We also found that features discovered using feature selection could be applied to other datasets with minor adjustments. In addition: we demonstrated that the performance of detection models decreased over time; we measured the change of websites in relation to our detection model; and we demonstrated the benefit of re-training in various scenarios.

Categories
Jobs/Internships

Post Doc Research Opportunity: Polymer-based Novel Drug Delivery Systems

Under the direction of Dr. Feng Zhang, Associate Professor of Molecular Pharmaceutics and Drug Delivery, the postdoctoral fellow will conduct research in polymer-based novel drug delivery systems. https://pharmacy.utexas.edu/directory/feng-zhang 


Essential function: 

  • 70% polymer-based novel drug delivery system: Our projects focus on process design and material characterization of polymer-based biodegradable and retrievable implants for long-acting drug delivery. They involve various manufacturing techniques such as extrusion, injection molding, 3-D printing, and nano-manufacturing. The post-doc fellow will be in charge of study planning, experiment execution, and data analysis. 
  • 15% Assist with Managing Day to Day Operations: Assist with managing instrument operation and maintenance, and maintain lab supplies. 
  • 15% Supervision/Training: Assist in supervising and training students and laboratory staff members in routine laboratory techniques and safety practices. 


Required qualification:

  • Essential Qualifications: Ph.D. in polymer processing and engineering
  • Preferred Qualifications: Experience with compounding and characterizing polymeric materials. Experience in 3D printing and nano-manufacturing.

To apply, or if you have any questions about this position, please contact Dr. Zhang (zfsu@umd.edu).

Categories
Defenses

Dissertation Defense: Nicholas Jankowski

Title: Phase Change Materials For Vehicle And Electronic Transient Thermal Systems

Advisory Committee
Professor F. Patrick McCluskey, Chair
Professor Neil Goldsman (Dean’s Representative)
Professor Hugh Bruck
Professor Michael Ohadi
Professor Jungho Kim

Date & Time: November 5, 2020; 3:00-5:00pm 

Zoom Link: https://umd.zoom.us/j/91690449959?pwd=cUpZejJPOXdEdlJvMzhURVJ0c2U1dz09

Abstract:  Most vehicle operating environments are transient in
nature, yet traditional subsystem thermal management addresses peak
load conditions with steady-state designs.  The large, overdesigned
systems that result are increasingly unable to meet target system
size, weight and power demands.  Phase change thermal energy storage
is a promising technique for buffering thermal transients while
providing a functional thermal energy reservoir.  Despite significant
research over the half century, few phase change material (PCM) based
solutions have transitioned out of the research laboratory.  This work
explores the state of phase change materials research for vehicle and
electronics applications and develops design tool compatible modeling
approaches for applying these materials to electronics packaging.

This thesis begins with a comprehensive PCM review, including over 700
candidate materials across more than a dozen material classes, and
follows with a thorough analysis of transient vehicle thermal systems.
After identifying promising materials for each system with potential
for improvement in emissions reduction, energy efficiency, or thermal
protection, future material research recommendations are made
including improved data collection, alternative metrics, and increased
focus on metallic and solid-state PCMs for high-speed applications.

Following the material and application review, the transient
electronics heat transfer problem is specifically addressed.
Electronics packages are shown using finite element based thermal
circuits to exhibit both worsened response and extreme convective
insensitivity under pulsed conditions.  Both characteristics are
quantified using analytical and numerical transfer function models,
including both clarification of apparently nonphysical thermal
capacitance and demonstration that the convective insensitivity can be
quantified using a package thermal Elmore delay metric.

Finally, in order to develop design level PCM models, an energy
conservative polynomial smoothing function is developed for Enthalpy
and Apparent Capacity Method phase change models.  Two case studies
using this approach examine the incorporation of PCMs into electronics
packages: substrate integrated Thermal Buffer Heat Sinks using
standard finite element modeling, and direct on-die PCM integration
using a new phase change thermal circuit model.  Both show
effectiveness in buffering thermal transients, but the metallic phase
change materials exhibit the best performance with significant
sub-millisecond temperature suppression, something improved cooling or package integration alone were unable to address.

Categories
Announcements Workshops, Seminars, & Events

Future Leaders in Mechanical and Aerospace Engineering: Celebrating Diversity and Innovation

A NATIONAL WEBINAR SERIES  |  #MAEFutureLeaders
Wednesday, Oct. 14, 2020 – 11:00 a.m. PST / 2:00 p.m. EST

Join the webinar: http://bit.ly/MAEFutureLeaders

Sofia Arevalo

Ph.D. Student
Department of Mechanical Engineering

U.C. Berkeley

“Nanoindentation of Orthopedic Polymers: Mechanical Properties at the Macro-, Micro- and Nano-length Scales”
 

Nosakhare Edoimioya 

Ph.D. Student 
Department of Mechanical Engineering

University of Michigan
 
“Data-Driven Control for High-Throughput Additive Manufacturing” 

Each Presentation will be 20 minutes followed by a questions and answer period


Host: Professor Howard A. Stone

Donald R. Dixon ’69 and Elizabeth W. Dixon Professor in Mechanical and Aerospace Engineering, Princeton University


About Future Leaders in Mechanical and Aerospace Engineering: Celebrating Diversity and Innovation:This nationwide online seminar series will highlight research contributions by graduate students and postdocs from groups that are underrepresented within Mechanical Engineering and Aerospace Engineering. In addition to providing exposure and mentorship opportunities to the speakers, the seminar series will create a network among underrepresented students, postdocs and faculty in Mechanical and Aerospace Engineering departments across the country. The organizing committee asks that you please nominate speakers for the seminar series or volunteer to mentor speakers using the MAEFutureLeaders website.

Website  |  Sign up for mailing list  |  Twitter: #MAEFutureLeaders
 Questions? Email the seminar series organizers.

John Dabiri(Caltech)  | Samuel Graham(Georgia Tech) 
Allison Okamura (Stanford University)  |  Howard Stone (Princeton University)