Engineering Commons^™

Environmental Systems Modeling And Management - University Of Virginia, Charlottesville, Teresa Culver

All ECSTATIC Materials

Grad/Undergrad course in environmental systems modeling and management offered at University of Virginia, Charlottesville in Fall 2013.

Deterministic Optimization And Design - University Of California, Davis, Jay R. Lund

All ECSTATIC Materials

Undergraduate course in deterministic optimization and design offered at U.C. Davis.

Computational Optogenetics: Empirically-Derived Voltage- And Light-Sensitive Channelrhodopsin-2 Model, John C. Williams, Jianjin Xu, Zhongju Lu, Aleksandra Klimas, Xuxin Chen, Christina M. Ambrosi, Ira S. Cohen, Emilia Entcheva

Department of Biomedical Engineering Faculty Publications

Channelrhodospin-2 (ChR2), a light-sensitive ion channel, and its variants have emerged as new excitatory optogenetic tools not only in neuroscience, but also in other areas, including cardiac electrophysiology. An accurate quantitative model of ChR2 is necessary for in silicoprediction of the response to optical stimulation in realistic tissue/organ settings. Such a model can guide the rational design of new ion channel functionality tailored to different cell types/tissues. Focusing on one of the most widely used ChR2 mutants (H134R) with enhanced current, we collected a comprehensive experimental data set of the response of this ion channel to different irradiances and voltages, …

Tools And Methods To Optimize The Analysis Of Telescopic Performance Metrics On Sofia, Steven R. Wilson, Holger Jakob, Stefan Teufel, Zaheer Ali, Jeffrey Van Cleve, Brian Eney, Greg Perryman

STAR Program Research Presentations

SOFIA is an infrared observatory mounted on a modified 747 engineered to do infrared astronomy at 45000 feet. The telescope equipment contains a number of sensors and stabilizers that allow the telescope to capture images while mounted in a moving plane. We have developed methods to analyze the performance of the telescope assembly that will help improve the stabilization and image capturing performance of the observatory. Here we present reusable methods to analyze telescope performance data that will enable improvements in the quality of the scientific data that is produced by the SOFIA. This poster focuses on the multi-flight performance …

Decomposed Lifting-Line Predictions And Optimization For Propulsive Efficiency Of Flapping Wings, W. F. Phillips, R. A. Miller, Doug F. Hunsaker

Mechanical and Aerospace Engineering Faculty Publications

A decomposed Fourier series solution to Prandtl's classical lifting-line theory is used to predict the lift, induced-thrust, and power coefficients developed by a flapping wing. A significant advantage of this quasi-steady analytical solution over commonly used numerical methods is the utility provided for optimizing wing flapping cycles. The analytical solution involves five time-dependent functions that could all be optimized to maximize thrust, propulsive efficiency, and/or other performance measures. Results show that by optimizing only two of these five functions, propulsive efficiencies exceeding 97% can be obtained. Results are presented for untwisted rectangular wings in pure plunging, rectangular wings with linear …

Reliability-Based Design Optimization Of Concrete Flexural Members Reinforced With Ductile Frp Bars, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

In recent years, ductile hybrid FRP (DHFRP) bars have been developed for use as tensile reinforcement. However, initial material costs regain high, and it is difficult to simultaneously meet strength, stiffness, ductility, and reliability demands. In this study, a reliability-based design optimization (RBDO) is conducted to determine minimum cost DHFRP bar configurations while enforcing essential constraints. Applications for bridge decks and building beams are considered, with 2, 3, and 4-material bars. It was found that optimal bar configuration has little variation for the different applications, and that overall optimized bar cost decreased as the number of bar materials increased.

Master Physician Scheduling Problem, Aldy Gunawan, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

We study a real-world problem arising from the operations of a hospital service provider, which we term the master physician scheduling problem. It is a planning problem of assigning physicians’ full range of day-to-day duties (including surgery, clinics, scopes, calls, administration) to the defined time slots/shifts over a time horizon, incorporating a large number of constraints and complex physician preferences. The goals are to satisfy as many physicians’ preferences and duty requirements as possible while ensuring optimum usage of available resources. We propose mathematical programming models that represent different variants of this problem. The models were tested on a real …

Wireless Sensor Network Deployment, Yipeng Qu

FIU Electronic Theses and Dissertations

Wireless Sensor Networks (WSNs) are widely used for various civilian and military applications, and thus have attracted significant interest in recent years. This work investigates the important problem of optimal deployment of WSNs in terms of coverage and energy consumption. Five deployment algorithms are developed for maximal sensing range and minimal energy consumption in order to provide optimal sensing coverage and maximum lifetime. Also, all developed algorithms include self-healing capabilities in order to restore the operation of WSNs after a number of nodes have become inoperative.

Two centralized optimization algorithms are developed, one based on Genetic Algorithms (GAs) and one …

Water Demand And Allocation In The Mara River Basin, Kenya/Tanzania In The Face Of Land Use Dynamics And Climate Variability, Shimelis B. Dessu

FIU Electronic Theses and Dissertations

The Mara River Basin (MRB) is endowed with pristine biodiversity, socio-cultural heritage and natural resources. The purpose of my study is to develop and apply an integrated water resource allocation framework for the MRB based on the hydrological processes, water demand and economic factors. The basin was partitioned into twelve sub-basins and the rainfall runoff processes was modeled using the Soil and Water Assessment Tool (SWAT) after satisfactory Nash-Sutcliff efficiency of 0.68 for calibration and 0.43 for validation at Mara Mines station. The impact and uncertainty of climate change on the hydrology of the MRB was assessed using SWAT and …

Light Reflection Is Nonlinear Optimization, Jiakun Liu

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we show that the near field reflector problem is a nonlinear optimization problem. From the corresponding functional and constraint function, we derive the Monge-Ampère type equation for such a problem.

Synthesis And Optimization Of Pedot:Pss Based Ink For Printing Nanoarrays Using Dip-Pen Nanolithography, Michal Wagner, Cathal O'Connell, David G. Harman, Ryan Sullivan, Ari Ivaska, Michael J. Higgins, Gordon G. Wallace

Faculty of Engineering and Information Sciences - Papers: Part A

Due to the current interest in organic printable electronics, Dip-Pen Nanolithography (DPN) is increasingly being explored as a method to pattern electroactive materials such as conducting polymers (CPs) on the micro- and nanoscale. In general, printing process depends strongly on the ink-substrate properties and fundamental forces required to drive and stabilize the ink transfer to the substrate. Controlling these parameters is especially difficult when operating under the nanometer confinements of the DPN probe. For the printing of CPs, one step towards addressing these challenges is rational ink design, as the use of existing commercial-based inks may not be suitable for …

Sizing Optimization Of Trapezoidal Corrugated Roof Sheeting, Supporting Solar Panels, Under Wind Loading, P Sharafi, Lip H. Teh, Muhammad N. S Hadi

Faculty of Engineering and Information Sciences - Papers: Part A

The dimensions of trapezoidal roof sheeting supporting solar panels are optimized so that a minimum amount of steel is required for a specific range of wind loads. Sheets of different grades and different thicknesses along with different ranges of wind speeds are considered. In order to simulate the behavior of the corrugated sheets analysis is carried out for two limit states: strength and serviceability. For both limit states, the objective is to minimize the weight per unit area of the panels. First, optimum cross-section is obtained to meet the strength conditions. Then the deflection is controlled for serviceability. The optimum …

Advances In Whole Abdominal Irradiation: What Protons, Vmat, And Imrt Using Multicriteria Optimization Can Offer, N Rochet, E Batin, N Depauw, K Jee, H M. Kooy, F H. Khan, P J. Paetzold, A H. Russell, T R. Bortfeld, D L. Craft

Faculty of Engineering and Information Sciences - Papers: Part A

Abtract of paper presented 55th Annual Meeting of the American Society for Radiation Oncology 2013.

A Methodology For Cost Optimization Of The Layout Design Of Multi-Span Reinforced Concrete Beams, Pezhman Sharafi, Muhammad Hadi, Lip H. Teh

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a description of a new methodology for the optimum preliminary layout design of reinforced concrete multi-span beams considering the relevant cost elements. First, a new objective function is presented, as an alternative to traditional cost functions for reinforced concrete beams. The ability of being easily employed in layout optimization problems, gives the new cost function a distinct advantage over its alternatives. Examples are included to illustrate the performance of the new methodology.

Modelling Of Polyaniline For Wi-Fi Electromagnetic Interference Shielding, Whamid Al-Shabib, Stefan W. Lachowicz

Research outputs 2013

In this paper COMSOL model is used to model the s-parameters of the electromagnetic shielding of layer/layers of Polyaniline (PAni) for Wi-Fi Electromagnetic Interference (EMI) shielding. PAni has a good future for minimizing the problems with Electromagnetic Shielding (EMS), and will be increasingly be used to provide protection from Electromagnetic Radiation (EMR) and Electromagnetic Interference (EMI). With the increased development in Wi-Fi and telecommunications equipment, a simple model is required to test for transmission losses. In this paper the electromagnetic radiation from antenna, positioned 30cm from PAni shielding device is modelled using COMSOL 4.2. The paper predicts the radiation reduction …

Transferability Of Jarvis-Type Models Developed And Re-Parameterized For Maize To Estimate Stomatal Resistance Of Soybean: Analyses On Model Calibration, Validation, Performance, Sensitivity, And Elasticity, Denis Mutiibwa, Suat Irmak

Biological Systems Engineering: Papers and Publications

In a previous study by the same authors, a new modified Jarvis model (NMJ-model) was developed, calibrated, and validated to estimate stomatal resistance (rs) for maize canopy on an hourly time step. The NMJ-model’s unique subfunctions, different from the original Jarvis model (J-model), include a photosynthetic photon flux density

(PPFD)-r_s response subfunction developed from field measurements and a new physical term, Aexp(1/LAI), where A is the minimum stomatal resistance and LAI is the green leaf area index, to account for the influence of canopy development on r_s, especially during partial canopy stage in the early season and …