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Full-Text Articles in Engineering

Projected Nesterov’S Proximal-Gradient Signal Recovery From Compressive Poisson Measurements, Renliang Gu, Aleksandar Dogandžić Nov 2015

Projected Nesterov’S Proximal-Gradient Signal Recovery From Compressive Poisson Measurements, Renliang Gu, Aleksandar Dogandžić

Aleksandar Dogandžić

We develop a projected Nesterov’s proximal-gradient (PNPG) scheme for reconstructing sparse signals from compressive Poisson-distributed measurements with the mean signal intensity that follows an affine model with known intercept. The objective function to be minimized is a sum of convex data fidelity (negative log-likelihood (NLL)) and regularization terms. We apply sparse signal regularization where the signal belongs to a nonempty closed convex set within the domain of the NLL and signal sparsity is imposed using total-variation (TV) penalty. We present analytical upper bounds on the regularization tuning constant. The proposed PNPG method employs projected Nesterov’s acceleration step, function restart, and …


Low-Cost Rural Surface Alternatives: Demonstration Project, Cheng Li, Jeramy C. Ashlock, David White, Pavana Vennapusa Jun 2015

Low-Cost Rural Surface Alternatives: Demonstration Project, Cheng Li, Jeramy C. Ashlock, David White, Pavana Vennapusa

Jeramy C. Ashlock

A field demonstration project was conducted in Hamilton County, Iowa to compare the relative performance, durability, and costs of several stabilization methods for preventing or mitigating freeze-thaw damage to granular surfaced roads.


Low-Cost Rural Surface Alternatives: Demonstration Project, Cheng Li, Jeramy C. Ashlock, David White, Pavana Vennapusa Jun 2015

Low-Cost Rural Surface Alternatives: Demonstration Project, Cheng Li, Jeramy C. Ashlock, David White, Pavana Vennapusa

Jeramy C. Ashlock

The goals of this project were to implement several stabilization methods for preventing or mitigating freeze-thaw damage to granular surfaced roads and identify the most effective and economical methods for the soil and climate conditions of Iowa. Several methods and technologies identified as potentially suitable for Iowa were selected from an extensive analysis of existing literature provided with Iowa Highway Research Board (IHRB) Project TR-632.Using the selected methods, demonstration sections were constructed in Hamilton County on a heavily traveled two-mile section of granular surfaced road that required frequent maintenance during previous thawing periods. Construction procedures and costs of the demonstration …


Assessment Of Nondestructive Testing Technologies For Quality Control/Quality Assurance Of Asphalt Mixtures - Tech Transfer Summary, Shibin Lin, Jeramy C. Ashlock, Hanjun Kim, Jeremy Nash, Hosin David Lee, R. Christopher Williams Mar 2015

Assessment Of Nondestructive Testing Technologies For Quality Control/Quality Assurance Of Asphalt Mixtures - Tech Transfer Summary, Shibin Lin, Jeramy C. Ashlock, Hanjun Kim, Jeremy Nash, Hosin David Lee, R. Christopher Williams

Jeramy C. Ashlock

Asphalt pavements suffer various failures due to insufficient quality within their design lives. The American Association of State Highway and Transportation Officials (AASHTO) Mechanistic-Empirical Pavement Design Guide (MEPDG) has been proposed to improve pavement quality through quantitative performance prediction. Evaluation of the actual performance (quality) of pavements requires in situ nondestructive testing (NDT) techniques that can accurately measure the most critical, objective, and sensitive properties of pavement systems. The purpose of this study is to assess existing as well as promising new NDT technologies for quality control/quality assurance (QC/QA) of asphalt mixtures. Specifically, this study examined field measurements of density …


Probing The Enzymatic Activity Of Alkaline Phosphatase Within Quantum Dot Bioconjugates, Jonathan C. Claussen, Anthony Malanoski, Joyce C. Breger, Eunkeu Oh, Scott A. Walper, Kimihiro Susumu, Ramasis Goswami, Jeffrey R. Deschamps, Igor L. Medintz Jan 2015

Probing The Enzymatic Activity Of Alkaline Phosphatase Within Quantum Dot Bioconjugates, Jonathan C. Claussen, Anthony Malanoski, Joyce C. Breger, Eunkeu Oh, Scott A. Walper, Kimihiro Susumu, Ramasis Goswami, Jeffrey R. Deschamps, Igor L. Medintz

Jonathan C. Claussen

Enzymes provide the critical means by which to catalyze almost all biological reactions in a controlled manner. Methods to harness and exploit their properties are of strong current interest to the growing field of biotechnology. In contrast to depending upon recombinant genetic approaches, a growing body of evidence suggests that apparent enzymatic activity can be enhanced when located at a nanoparticle interface. We use semiconductor quantum dots (QDs) as a well-defined and easily bioconjugated nanoparticle along with Escherichia coli-derived alkaline phosphatase (AP) as a prototypical enzyme to seek evidence for this process in a de novo model system. We began …