Announcements

Thesis Defense: Hwanpyo Kim “Simulation of non-Gaussian/non-stationary stochastic processes: beyond second-order orthogonality”

THE DEPARTMENT OF CIVIL ENGINEERING

AND

ADVISOR MICHAEL SHIELDS, ASST. PROFESSOR

ANNOUNCE THE THESIS DEFENSE OF

Doctoral Candidate

Hwanpyo Kim

Tuesday, April 24, 2018

12:00pm

Malone 107

“Simulation of non-Gaussian/non-stationary stochastic processes: beyond second-order orthogonality”

The theory of stochastic processes and their generations are indispensable to characterize wind fluctuations, ocean waves, and earthquake excitations among other quantities in engineering. To computationally analyze and simulate these stochastic systems, practical realization of samples of stochastic processes is essential. The object of this thesis is to introduce new state-of-the-art methodologies for the generation of stochastic processes with non-Gaussianity/non-stationarity possessing higher-order properties than the second-order orthogonality.

A new type of Iterative Translation Approximation Method (ITAM) using the Karhunen-Loève expansion was developed for simulating non-Gaussian and non-stationary processes utilizing translation process theory. The proposed methodology enhances the accuracy of simulated processes in matching a prescribed autocorrelation, maintains the computational efficiency, and resolves limitations caused by utilizing evolutionary power spectra for non-stationary processes.

A new generalized stochastic expansion, the bispectral representation method (BSRM), expanded from the traditional spectral representation method is introduced to simulate skewed nonlinear stochastic processes. With new orthogonal increments to satisfy the conditions of the Cramér spectral representation up to third order orthogonality, the BSRM generates samples that match both the power spectrum and bispectrum of the process by modeling complex nonlinear wave interactions.

A model of phase angle distributions to characterize phase coupling in higher-order stochastic processes is presented. Relationships between the trigonometric moments of circular distributions of phase differences and higher-order cumulant spectra are derived. The prescribed properties are shown to accurately model quadratic and cubic phase couplings in simple stochastic processes and can easily be extended to general n-wave couplings.

Lastly, as applications of the prescribed methods, wind pressure and turbulent wind velocity time histories are generated with SRM, ITAM, and BSRM and applied to two different nonlinear dynamic structural systems. For structures having material and geometrical nonlinearities, performance of an elastic perfectly-plastic structure and the buffeting response of a long-span bridge with coupled aerodynamic forces are examined. The structures are investigated to observe the effect of higher-order properties of the excitations on the response when compared to conventional second-order Gaussian and non-Gaussian excitations.

Thesis Defense: Wei Jang, “Machine Learning and Optimization for Healthcare and Energy Systems”

The Department of Civil Engineering
and
Advisor Sauleh Siddiqui, Assistant Professor
Announce the Thesis Defense of
Doctoral Candidate

 

Wei Jiang

Thursday, March 22, 2018

2:00-4:00pm

Latrobe 106

 

“Machine Learning and Optimization for Healthcare and Energy Systems

 

Abstract:

Healthcare and energy systems provide critical service to our society. Recent advancement in information technology has enabled these systems to keep retrieving and storing data. In this dissertation, we used machine learning, optimization techniques, and data from healthcare and energy systems to build predictive models and discover new knowledge to guide decision-making and improve the efficiency and sustainability of these systems. We also used optimization techniques to improve the efficiency of hyperparameter tuning for machine learning algorithms. Specifically, we built a dynamic daily prediction model for predicting heart failure patients’ 30-day readmission risk. We built a prediction model to predict xerostomia (dry mouth) for head and neck cancer patients treated with radiotherapy and identified the influence pattern of radiation dose across head and neck on xerostomia. Using an economic equilibrium model combined with optimization techniques for calibration, we built the first global trade model for wood chip and analyzed how local renewable energy policy in the United States could affect the global wood chip trade and lead to deforestation in other world regions. Finally, we created a new method for tuning the hyper-parameter for support vector machines by solving the problem as a bilevel optimization problem using stochastic gradient descent combined with dual coordinate descent method. We showed that the new method is more efficient than ad hoc empirical approaches. In summary, we demonstrated how machine learning and optimization techniques can improve the efficiency of healthcare and energy systems, and how optimization techniques can advance machine learning algorithms.

 

 

Spring 2018 Graduate Seminar Speaker Series

Below is a listing for the speakers being showcased during the Spring 2018 Civil Engineering Graduate Seminar Series. All civil engineering graduate seminars are FREE and open to the public. Attendance is required for all enrolled Civil Engineering graduate students. For information on individual seminars, please refer to the Events Calendar.

For directions and information on parking please see Maps & Directions link at www.jhu.edu and select information on Homewood Campus.

Thesis Defense: Reza Yaghmaie, “Multi-Temporal Multi-Physics Computational Framework For Fully Coupled Electric, Magnetic and Mechanical Systems With Evolving Damage”

THE DEPARTMENT OF CIVIL ENGINEERING

AND

ADVISOR SOMNATH GHOSH, PROFESSOR

ANNOUNCE THE THESIS DEFENSE OF

Doctoral Candidate

Reza Yaghmaie

Monday, December 18, 2017

1:00pm

Latrobe 106

“Multi-Temporal Multi-Physics Computational Framework For Fully Coupled Electric, Magnetic and Mechanical Systems With Evolving Damage”

 

 

MSE Essay Presentation: Johnpatrick Connors – “Variability in the Experimental Response of Thermally Excited Aluminum Alloys”

The Department of Civil Engineering

and

Advisor Michael Shields, Asst. Professor

Announce the Essay Presentation of

M.S.E. Candidate

 

Johnpatrick Connors

Monday, December 4, 2017

3:00-4:00pm

Latrobe 106

Variability in the Experimental Response of Thermally

Excited Aluminum Alloys”

 

The use of aluminum alloys for load bearing elements continues to expand rapidly across the marine, aviation, and commercial building industries, among others. Some factors driving this expansion are aluminum’s low density, good formability, and high corrosion resistance when properly alloyed and tempered. These properties give aluminum a number of competitive advantages, especially for light-weight structures such as airplanes and ships, as compared with other structural metals.

 

However, one factor hindering the expansion of aluminum alloys, especially in high temperature applications, is that is has a relatively low melting point. This, combined with a lack of knowledge regarding the uncertainty of aluminum’s performance at high temperatures often counteracts the weight savings provided by aluminum’s low density.

 

Existing studies of aluminum alloys have omitted discussion of the uncertainty in aluminum’s response to high temperature environments. In order to address this lack of data, this thesis presents experimental results of 100 tension tests and 54 plane strain tests of the most commonly used structural aluminum, 6061-T651 aluminum alloy.

 

Key results of the study include engineering stress-strain curves and statistics of mechanical properties obtained using digital image correlation. These statistics show the variation in the mechanical behavior of aluminum under two different stress states, six different temperatures, and between different batches of material.

Thesis Defense: Abdullah Mahmoud, “Analysis and Design of Spirally Welded Thin-Walled Steel Tapered Cylindrical Shells Under Bending with Application to Wind Turbine Towers”

THE DEPARTMENT OF CIVIL ENGINEERING

AND

ADVISOR BENJAMIN SCHAFER, PROFESSOR

ANNOUNCE THE THESIS DEFENSE OF

Doctoral Candidate

Abdullah Mahmoud

Monday, October 16, 2017

3:15pm – 5:15pm

Malone G33/35

“Analysis and Design of Spirally Welded Thin-Walled Steel Tapered Cylindrical Shells Under Bending with Application to Wind Turbine Towers”

Seeking Applicants for Tenure-Track/Tenured Faculty Positions with Emphasis in Systems Engineering

The Johns Hopkins University’s Department of Civil Engineering seeks applicants for tenure-track/tenured faculty positions at all levels and across all areas of Civil Engineering. While emphasis is in the area of Systems Engineering with particular interest in healthcare and/or infrastructure resilience, all qualified applicants in any area of Civil Engineering will be considered.

The Department of Civil Engineering has 11 faculty whose research broadly covers the areas of Structures, Systems, and Mechanics of Materials. Current enrollments in the Department are approximately 50 undergraduate students and 60 graduate students, the majority of which are Ph.D. candidates. The department maintains laboratories and major facilities for research. Strong links to JHU institutes and centers such as the Malone Center for Engineering in Healthcare, the Center for Systems Science and Engineering, the Center for Integrated Structures-Materials Modeling and Simulation, the Hopkins Extreme Materials Institute, and the Cold-formed Steel Research Consortium expand the footprint of the Department both within and outside of the University. More information about the Department of Civil Engineering can be found at http://www.ce.jhu.edu.

The Whiting School of Engineering comprises over 200 full time tenure-track, research, and teaching-track faculty in nine academic programs with a total annual research budget of over $100 million. Research partnerships with the Johns Hopkins School of Medicine, Applied Physics Laboratory, Bloomberg School of Public Health and the Krieger School of Arts and Sciences make the Whiting School of Engineering a unique research and educational environment. Student enrollment exceeds 1800 at the undergraduate level with over 1000 full time MS and PhD students. The Engineering for Professionals program enrolls over 2000 part time continuing education students and is the largest program of its kind in the country.

Applicants must hold an earned doctorate in an appropriate field by the time their appointment begins. Candidates must have a demonstrated record of outstanding independent research and excellence in teaching, professional service and translation. Applications at all levels will be considered; salary and rank will be commensurate with qualifications and experience. Applicants should submit a curriculum vitae, a research statement, a teaching statement, three recent publications, and complete contact information for at least three references. Applications must be made on-line at https://apply.interfolio.com/45609.

Candidates applying for associate or full professor positions should not provide any information for references. Candidates applying for the position of Assistant Professor should provide names and contact information of at least three (3) references. Review of applications will begin immediately.  While candidates who complete their applications by November 15, 2017 will receive full consideration, the Department will consider exceptional applicants at any time.

The Johns Hopkins University is committed to active recruitment of a diverse faculty and student body. The University is an Affirmative Action/Equal Opportunity Employer of women, minorities, protected veterans and individuals with disabilities and encourages applications from these and other protected group members. Consistent with the University’s goals of achieving excellence in all areas, we will assess the comprehensive qualifications of each applicant.

The Whiting School of Engineering and the Department of Civil Engineering are committed to building a diverse educational environment.

Fall 2017 Graduate Seminar Speakers Announced

Below is a listing for the speakers being showcased during the Fall 2017 Civil Engineering Graduate Seminar Series. All civil engineering graduate seminars are FREE and open to the public. Attendance is required for all enrolled Civil Engineering graduate students. For information on individual seminars, please refer to the Events Calendar.

For directions and information on parking please see Maps & Directions link at www.jhu.edu and select information on Homewood Campus.

Join Us at the 6th Annual Career Fair

Are you an employer interested in recruiting our civil engineers? Register today to secure your spot at the 6th Annual Department of Civil Engineering Career Fair!

Questions? Contact Amanda Jackson at ajack110@jhu.edu.

Seeking Applicants for Part-time Lecturer of Graduate-level Design Course

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The Department of Civil Engineering at the Johns Hopkins University seeks a Part-time Lecturer to develop and teach a new Master’s-level design course to be offered annually, starting in the Spring 2018 semester. The intent of the course is to expose graduate students to design tools, technology and concepts that will prepare them for leadership positions in top engineering companies. Students in the course will gain experience integrating fundamental analytical skills in the context of design. While the successful candidate will be expected to coordinate this course with the Department curriculum, they will also enjoy significant flexibility in developing a new course that suits their skills and interests. Requirements for the position include a master’s degree in civil engineering or related, and a minimum of 5 years experience in a design environment. Teaching experience is valued but not required. Compensation for offering a semester-long course is typically $8,000; however, extra funds may be negotiated in special circumstances (e.g., new course development time, travel to campus for instructors living outside the Baltimore metro area). Candidates should submit a CV or resume, with a cover letter that contains a brief summary of ideas for the proposed course. Applications must be made on-line at http://apply.interfolio.com/43104.

 

The Johns Hopkins University is committed to active recruitment of a diverse faculty and student body. The University is an Affirmative Action/Equal Opportunity Employer of women, minorities, protected veterans and individuals with disabilities and encourages applications from these and other protected group members.

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