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Computational Thinking Across The Curriculum: A Conceptual Framework, Amber Settle, Ljubomir Perkovic 2018 DePaul University

Computational Thinking Across The Curriculum: A Conceptual Framework, Amber Settle, Ljubomir Perkovic

Amber Settle

We describe a framework for implementing computational thinking in a broad variety of general education courses. The framework is designed to be used by faculty without formal training in information technology in order to understand and integrate computational thinking into their own general education courses. The framework includes examples of computational thinking in a variety of general education courses, as well as sample in-class activities, assignments, and other assessments for the courses. The examples in the different courses are related and differentiated using categories taken from Peter Denning’s Great Principles of Computing, so that similar types of computational thinking ...


Rethinking The Street In An Era Of Driverless Cars, Marc Schlossberg, William W. Riggs, Adam Millard-Ball, Elizabeth Shay 2018 University of Oregon

Rethinking The Street In An Era Of Driverless Cars, Marc Schlossberg, William W. Riggs, Adam Millard-Ball, Elizabeth Shay

William W. Riggs

Global citizens get few moments to rethink streets and make decisions that will both serve the basic purposes of transportation and address urgent challenges like climate change, rising obesity, social isolation and conflict— all while expanding opportunities for general happiness throughout society. Such a pivotal moment is upon us, as autonomous vehicles represent a potentially disruptive technology that can re-make the city for good or for ill. City planners, policy makers and community residents have a unique, and immediate, opportunity to rethink their streets with purposeful and creative consideration about how this critical public good may best serve the public ...


Deep Gaze Velocity Analysis During Mammographic Reading For Biometric Identification Of Radiologists, Hong-Jun Yoon, Folami Alamudun, Kathy Hudson, Garnetta Morin-Ducote, Georgia Tourassi 2018 Biomedical Sciences, Engineering, and Computing Group Health Data Sciences Institute, Oak Ridge National Laboratory

Deep Gaze Velocity Analysis During Mammographic Reading For Biometric Identification Of Radiologists, Hong-Jun Yoon, Folami Alamudun, Kathy Hudson, Garnetta Morin-Ducote, Georgia Tourassi

Journal of Human Performance in Extreme Environments

Several studies have confirmed that the gaze velocity of the human eye can be utilized as a behavioral biometric or personalized biomarker. In this study, we leverage the local feature representation capacity of convolutional neural networks (CNNs) for eye gaze velocity analysis as the basis for biometric identification of radiologists performing breast cancer screening. Using gaze data collected from 10 radiologists reading 100 mammograms of various diagnoses, we compared the performance of a CNN-based classification algorithm with two deep learning classifiers, deep neural network and deep belief network, and a previously presented hidden Markov model classifier. The study showed that ...


Employing A User-Centered Design Process For Cybersecurity Awareness In The Power Grid, Jean C. Scholtz, Lyndsey Franklin, Aditya Ashok, Katya LeBlanc, Christopher Bonebrake, Eric Andersen, Michael Cassiadoro 2018 Pacific Northwest National Laboratory

Employing A User-Centered Design Process For Cybersecurity Awareness In The Power Grid, Jean C. Scholtz, Lyndsey Franklin, Aditya Ashok, Katya Leblanc, Christopher Bonebrake, Eric Andersen, Michael Cassiadoro

Journal of Human Performance in Extreme Environments

In this paper, we discuss the process we are using in the design and implementation of a tool to improve the situation awareness of cyberattacks in the power grid. We provide details of the steps we have taken to date and describe the steps that still need to be accomplished. The focus of this work is to provide situation awareness of the power grid to staff from different, non-overlapping roles in an electrical transmission organization in order to facilitate an understanding of a possible occurrence of a cyberattack. Our approach follows a user-centered design process and includes determining the types ...


Prairie Strips Improve Biodiversity And The Delivery Of Multiple Ecosystem Services From Corn–Soybean Croplands, Lisa A. Schulte, Jarad Niemi, Matthew J. Helmers, Matt Liebman, J. Gordon Arbuckle, David E. James, Randall K. Kolka, Matthew E. O'Neal, Mark D. Tomer, John C. Tyndall, Heidi Asbjornsen, Pauline Drobney, Jeri Neal, Chris Witte 2018 Iowa State University

Prairie Strips Improve Biodiversity And The Delivery Of Multiple Ecosystem Services From Corn–Soybean Croplands, Lisa A. Schulte, Jarad Niemi, Matthew J. Helmers, Matt Liebman, J. Gordon Arbuckle, David E. James, Randall K. Kolka, Matthew E. O'Neal, Mark D. Tomer, John C. Tyndall, Heidi Asbjornsen, Pauline Drobney, Jeri Neal, Chris Witte

Jarad Niemi

Loss of biodiversity and degradation of ecosystem services from agricultural lands remain important challenges in the United States despite decades of spending on natural resource management. To date, conservation investment has emphasized engineering practices or vegetative strategies centered on monocultural plantings of nonnative plants, largely excluding native species from cropland. In a catchment-scale experiment, we quantified the multiple effects of integrating strips of native prairie species amid corn and soybean crops, with prairie strips arranged to arrest run-off on slopes. Replacing 10% of cropland with prairie strips increased biodiversity and ecosystem services with minimal impacts on crop production. Compared with ...


Ionic Depletion At The Crystalline Gibbs Layer Of Peg-Capped Gold Nanoparticle Brushes At Aqueous Surfaces, Wenjie Wang, Honghu Zhang, Surya Mallapragada, Alex Travesset, David Vaknin 2018 Ames Laboratory

Ionic Depletion At The Crystalline Gibbs Layer Of Peg-Capped Gold Nanoparticle Brushes At Aqueous Surfaces, Wenjie Wang, Honghu Zhang, Surya Mallapragada, Alex Travesset, David Vaknin

Surya K. Mallapragada

In situ surface-sensitive x-ray diffraction and grazing incidence x-ray fluorescence spectroscopy (GIXFS) methods are combined to determine the ionic distributions across the liquid/vapor interfaces of thiolated-polyethylene-glycol–capped gold nanoparticle (PEG-AuNP) solutions. Induced by the addition of salts (i.e., Cs2SO4) to PEG-AuNPs solutions, two-dimensional hexagonal lattices of PEG-AuNPs form spontaneously at the aqueous surfaces, as is demonstrated by x-ray reflectivity and grazing incidence small-angle x-ray scattering. By taking advantage of element specificity with the GIXFS method, we find that the cation Cs+ concentration at the crystalline film is significantly reduced in parts of the PEG-AuNP film compared with that ...


Effect Of Stacking Fault Energy On Mechanism Of Plastic Deformation In Nanotwinned Fcc Metals, Valery Borovikov, Mikhail I. Mendelev, Alexander H. King, Richard A. Lesar 2018 The Ames Laboratory

Effect Of Stacking Fault Energy On Mechanism Of Plastic Deformation In Nanotwinned Fcc Metals, Valery Borovikov, Mikhail I. Mendelev, Alexander H. King, Richard A. Lesar

Richard Alan Lesar

Starting from a semi-empirical potential designed for Cu, we have developed a series of potentials that provide essentially constant values of all significant (calculated) materials properties except for the intrinsic stacking fault energy, which varies over a range that encompasses the lowest and highest values observed in nature. These potentials were employed in molecular dynamics (MD) simulations to investigate how stacking fault energy affects the mechanical behavior of nanotwinned face-centered cubic (FCC) materials. The results indicate that properties such as yield strength and microstructural stability do not vary systematically with stacking fault energy, but rather fall into two distinct regimes ...


Modeling Of Ti-W Solidification Microstructures Under Additive Manufacturing Conditions, Matthew R. Rolchigo, Michael Mendoza, Peyman Samimi, David A. Brice, Peter C. Collins, Richard Lesar 2018 Iowa State University

Modeling Of Ti-W Solidification Microstructures Under Additive Manufacturing Conditions, Matthew R. Rolchigo, Michael Mendoza, Peyman Samimi, David A. Brice, Peter C. Collins, Richard Lesar

Richard Alan Lesar

Additive manufacturing (AM) processes have many benefits for the fabrication of alloy parts, including the potential for greater microstructural control and targeted properties than traditional metallurgy processes. To accelerate utilization of this process to produce such parts, an effective computational modeling approach to identify the relationships between material and process parameters, microstructure, and part properties is essential. Development of such a model requires accounting for the many factors in play during this process, including laser absorption, material addition and melting, fluid flow, various modes of heat transport, and solidification. In this paper, we start with a more modest goal, to ...


Microstructures And Grain Refinement Of Additive-Manufactured Ti-Xw Alloys, Michael Mendoza, Peyman Samimi, David A. Brice, Brian Martin, Matthew R. Rolchigo, Richard Lesar, Peter C. Collins 2018 Iowa State University

Microstructures And Grain Refinement Of Additive-Manufactured Ti-Xw Alloys, Michael Mendoza, Peyman Samimi, David A. Brice, Brian Martin, Matthew R. Rolchigo, Richard Lesar, Peter C. Collins

Richard Alan Lesar

It is necessary to better understand the composition–processing–microstructure relationships that exist for materials produced by additive manufacturing. To this end, Laser Engineered Net Shaping (LENS™), a type of additive manufacturing, was used to produce a compositionally graded titanium binary model alloy system (Ti-xW specimen (0 ≤ x ≤ 30 wt pct), so that relationships could be made between composition, processing, and the prior beta grain size. Importantly, the thermophysical properties of the Ti-xW, specifically its supercooling parameter (P) and growth restriction factor (Q), are such that grain refinement is expected and was observed. The systematic, combinatorial study of this binary ...


Effect Of Stacking Fault Energy On Mechanism Of Plastic Deformation In Nanotwinned Fcc Metals, Valery Borovikov, Mikhail I. Mendelev, Alexander H. King, Richard A. Lesar 2018 The Ames Laboratory

Effect Of Stacking Fault Energy On Mechanism Of Plastic Deformation In Nanotwinned Fcc Metals, Valery Borovikov, Mikhail I. Mendelev, Alexander H. King, Richard A. Lesar

Alexander H. King

Starting from a semi-empirical potential designed for Cu, we have developed a series of potentials that provide essentially constant values of all significant (calculated) materials properties except for the intrinsic stacking fault energy, which varies over a range that encompasses the lowest and highest values observed in nature. These potentials were employed in molecular dynamics (MD) simulations to investigate how stacking fault energy affects the mechanical behavior of nanotwinned face-centered cubic (FCC) materials. The results indicate that properties such as yield strength and microstructural stability do not vary systematically with stacking fault energy, but rather fall into two distinct regimes ...


Electrical Stimulus Controlled Binding/Unbinding Of Human Thrombin-Aptamer Complex, Pranav Shrotriya, Agnivo Gosai, Xiao Ma, Ganesh Balasubraminian 2018 Iowa State University

Electrical Stimulus Controlled Binding/Unbinding Of Human Thrombin-Aptamer Complex, Pranav Shrotriya, Agnivo Gosai, Xiao Ma, Ganesh Balasubraminian

Pranav Shrotriya

The binding/unbinding of the human thrombin and its 15-mer single stranded DNA aptamer, under the application of external stimulus in the form of electrostatic potential/electric field, is investigated by a combination of continuum analysis and atomistic molecular dynamics simulation. In agreement with the experiments that demonstrate the influence of electrostatic potential on the thrombin/aptamer complex, our computations show that the application of positive electric field successfully unbinds the thrombin from the aptamer. Results from umbrella sampling simulations reveal that there is a decrease in the free energy of binding between the thrombin and aptamer in presence of ...


Ultrahard Polycrystalline Cubic Boron Nitride Composite Through Hybrid Laser/Waterjet Heat (Lwh) Treatment, Jingnan Zhao, Pranav Shrotriya 2018 Iowa State University

Ultrahard Polycrystalline Cubic Boron Nitride Composite Through Hybrid Laser/Waterjet Heat (Lwh) Treatment, Jingnan Zhao, Pranav Shrotriya

Pranav Shrotriya

Ultra-hard materials that are chemically inert and thermally stable at high temperatures are desirable for enhancing machining and wear performance in demanding chemical and thermal environments. Single and polycrystalline diamonds are the hardest tool materials; however, at high temperatures, diamond reacts with ferrous alloys, losing its chemical inertness and thermal stability. In contrast, cubic boron nitride (cBN) has exceptional chemical and thermal stability but has much lower hardness (35-45 GPa). Increasing the hardness of BN is expected to fill the property gap in state-of-the-art tool materials as shown and to generate huge industrial interest for meeting the stringent design requirements ...


Gene Regulatory Network Inference From Perturbed Time-Series Expression Data Via Ordered Dynamical Expansion Of Non-Steady State Actors, Mahdi Zamanighomi, Mostafa Zamanian, Michael J. Kimber, Zhengdao Wang 2018 Stanford University

Gene Regulatory Network Inference From Perturbed Time-Series Expression Data Via Ordered Dynamical Expansion Of Non-Steady State Actors, Mahdi Zamanighomi, Mostafa Zamanian, Michael J. Kimber, Zhengdao Wang

Zhengdao Wang

The reconstruction of gene regulatory networks from gene expression data has been the subject of intense research activity. A variety of models and methods have been developed to address different aspects of this important problem. However, these techniques are narrowly focused on particular biological and experimental platforms, and require experimental data that are typically unavailable and difficult to ascertain. The more recent availability of higher-throughput sequencing platforms, combined with more precise modes of genetic perturbation, presents an opportunity to formulate more robust and comprehensive approaches to gene network inference. Here, we propose a step-wise framework for identifying gene-gene regulatory interactions ...


Joint Optimization Of Power Allocation And Training Duration For Uplink Multiuser Mimo Communications, Songtao Lu, Zhengdao Wang 2018 Iowa State University

Joint Optimization Of Power Allocation And Training Duration For Uplink Multiuser Mimo Communications, Songtao Lu, Zhengdao Wang

Zhengdao Wang

In this paper, we consider a multiuser multiple-input multiple-output (MU-MIMO) communication system between a base station equipped with multiple antennas and multiple mobile users each equipped with a single antenna. The uplink scenario is considered. The uplink channels are acquired by the base station through a training phase. Two linear processing schemes are considered, namely maximum-ratio combining (MRC) and zero-forcing (ZF). We optimize the training period and optimal training energy under the average and peak power constraint so that an achievable sum rate is maximized.


A Nonconvex Splitting Method For Symmetric Nonnegative Matrix Factorization: Convergence Analysis And Optimality, Songtao Lu, Mingyi Hong, Zhengdao Wang 2018 Iowa State University

A Nonconvex Splitting Method For Symmetric Nonnegative Matrix Factorization: Convergence Analysis And Optimality, Songtao Lu, Mingyi Hong, Zhengdao Wang

Zhengdao Wang

Symmetric nonnegative matrix factorization (SymNMF) has important applications in data analytics problems such as document clustering, community detection, and image segmentation. In this paper, we propose a novel nonconvex variable splitting method for solving SymNMF. The proposed algorithm is guaranteed to converge to the set of Karush-Kuhn-Tucker (KKT) points of the nonconvex SymNMF problem. Furthermore, it achieves a global sublinear convergence rate. We also show that the algorithm can be efficiently implemented in parallel. Further, sufficient conditions are provided that guarantee the global and local optimality of the obtained solutions. Extensive numerical results performed on both synthetic and real datasets ...


Many Access For Small Packets Based On Precoding And Sparsity-Aware Recovery, Ronggui Xie, Huarui Yin, Xiaohui Chen, Zhengdao Wang 2018 Chinese Academy of Sciences

Many Access For Small Packets Based On Precoding And Sparsity-Aware Recovery, Ronggui Xie, Huarui Yin, Xiaohui Chen, Zhengdao Wang

Zhengdao Wang

Modern mobile terminals produce massive small data packets. For these short-length packets, it is inefficient to follow the current multiple access schemes to allocate transmission resources due to heavy signaling overhead. We propose a non-orthogonal many-access scheme that is well suited for the future communication systems equipped with many receive antennas. The system is modeled as having a block-sparsity pattern with unknown sparsity level (i.e., unknown number of transmitted messages). Block precoding is employed at each single-antenna transmitter to enable the simultaneous transmissions of many users. The number of simultaneously served active users is allowed to be even more ...


Degrees Of Freedom Region Of Wireless X Networks Based On Real Interference Alignment, Mahdi Zamanighomi, Zhengdao Wang 2018 Stanford University

Degrees Of Freedom Region Of Wireless X Networks Based On Real Interference Alignment, Mahdi Zamanighomi, Zhengdao Wang

Zhengdao Wang

We first consider a single hop wireless X network with K transmitters and J receivers, all with a single antenna. Each transmitter conveys an independent message for each receiver. The channel is assumed to have constant coefficients. We develop an interference alignment scheme for this setup and derive an achievable degrees of freedom (DoF) region. We show that in some cases, the derived region meets a previous outer bound, and hence, is the (exact) DoF region. For our achievability schemes, we divide each message into streams and use real interference alignment on the streams. Several previous results on the DoF ...


Double Hysteresis Loops At Room Temperature In Nanbo3-Based Lead-Free Antiferroelectric Ceramics, Xiaoli Tan, Zunping Xu, Xiaoming Liu, Zhongming Fan 2018 Iowa State University

Double Hysteresis Loops At Room Temperature In Nanbo3-Based Lead-Free Antiferroelectric Ceramics, Xiaoli Tan, Zunping Xu, Xiaoming Liu, Zhongming Fan

Xiaoli Tan

Polarization-field double hysteresis loops have hardly ever been observed at room temperature in polycrystalline NaNbO3, one of a few lead-free antiferroelectric compounds. In this Letter, it is shown that the exposure of a modified NaNbO3 ceramic to bipolar electric fields of ±160 kV/cm at 100°C can preserve the double hysteresis loops at room temperature. These double hysteresis loops can still be observed after 125 days room temperature aging with some decay in maximum polarization. Frequency dependence analysis suggests that the double hysteresis loops originate from the antiferroelectric ↔ ferroelectric phase transition, not the charged defects. A novel electrical treatment ...


Nonequilibrium Polarization Dynamics In Antiferroelectrics, M. M. Vopson, Xiaoli Tan 2018 University of Portsmouth

Nonequilibrium Polarization Dynamics In Antiferroelectrics, M. M. Vopson, Xiaoli Tan

Xiaoli Tan

A nonequilibrium statistical domain nucleation model of polarization dynamics in less understood antiferroelectric systems is introduced. Predictions of the model have been successfully tested experimentally using an antiferroelectric Pb0.99Nb0.02[( Zr0.57Sn0.43) Ti-0.94(0.06)] O-0.98(3) polycrystalline ceramic. We determined the activation energy of the domain nucleation process for this particular antiferroelectric sample to be W-b = 1.07 eV and the critical volume of the polar nucleus V * = 98 x 10(-27)m(3), which corresponds to a linear length scale of 2.86 nm.


Modeling The Interphase Of A Polymer-Based Nanodielectric, Connor S. Daily, Weixing Sun, Michael R. Kessler, Xiaoli Tan, Nicola Bowler 2018 Iowa State University

Modeling The Interphase Of A Polymer-Based Nanodielectric, Connor S. Daily, Weixing Sun, Michael R. Kessler, Xiaoli Tan, Nicola Bowler

Xiaoli Tan

A three-phase theoretical model is proposed that is suitable for describing the effective permittivity of polymer-matrix composites containing spherical nanoparticles. The model accounts for the presence of an interphase region, which surrounds each nanosphere, whose permittivity is allowed to be different from that of the matrix polymer. The nanoparticles themselves are approximated as hard (non-overlapping) spheres, whereas the interphase regions of neighboring nanoparticles are permitted to overlap. The volume fraction of the interphase region is computed by assuming that the nanoparticles are arranged on the nodes of a simple-cubic lattice. The effective permittivity of the composite is subsequently computed via ...


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