Physical Sciences and Mathematics Commons^™

A Framework Architecture For Student Learning In Distributed Embedded Systems, William L. Honig, Konstantin Läufer, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

Academic courses focused on individual microcomputers or client/server applications are no longer sufficient for students to develop knowledge in embedded systems. Current and near-term industrial systems employ multiple interacting components and new network and security approaches; hence, academic preparation requires teaching students to develop realistic projects comparable to these real-world products. However, the complexity, breadth, and technical variations of these real-world products are difficult to reproduce in the classroom. This paper outlines preliminary work on a framework architecture suitable for academic teaching of modern embedded systems including the Internet of Things. It defines four layers, two of which are at …

Paraxial Full-Field Cloaking, Joseph S. Choi, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We complete the ‘paraxial’ (small-angle) ray optics cloaking formalism presented previously [Opt. Express 22, 29465 (2014)], by extending it to the full-field of light. Omnidirectionality is then the only relaxed parameter of what may be considered an ideal, broadband, field cloak. We show that an isotropic plate of uniform thickness, with appropriately designed refractive index and dispersion, can match the phase over the whole visible spectrum. Our results support the fundamental limits on cloaking for broadband vs. omnidirectionality, and provide insights into when anisotropy may be required.

Spectroscopic Characterization Of A Radio-Frequency Argon Plasma Jet Discharge In Ambient Air, Patrick Cullen, Vladimir Milosavljevic

Articles

This study includes a detailed experimental investigation of the spatial and temporal spectroscopic emission of an argon plasma jet discharge. The study is carried out in ambient air and quenching by inflowing air species is considered. The optical emission spectroscopy of neutral atomic spectral lines and molecular bands, over a range of plasma process parameters, is investigated. Wavelength-resolved argon optical emission profiles are used to monitor the electron energy distribution function and the density of argon metastable atoms. The experimental data indicates that the argon flow rate, in a confined open-air plasma discharge, limits the impact of molecular oxygen in …

Effect Of The Condensation Of Hybrid Organic–Inorganic Sol–Gel Materials On The Optical Properties Of Tripan Blue, Craig Hicks, Muhammad Morshed, Garrett Melia, Killian Barton, Brendan Duffy, Mohamed Oubaha

Articles

The work reported in this paper highlights the effect of sol–gel structures on the optical properties of a typical organic dye (Trypan Blue, TB). Three transition-metal-based hybrid sol–gel materials with different structures and morphologies were developed and characterised by TEM. The optical properties of TB were investigated by incorporating it in the different sol–gel materials and the UV–Visible spectra recorded in both liquid and solid state, in thin-coatings cured at temperatures in the range 100– 150 [1]C. These studies revealed two relevant results. First, the sol–gel morphology plays a critical role in the optical properties of the dye. The effect …

How Realistic Is Photorealistic?, Olivia B. Holmes

Dartmouth College Undergraduate Theses

From its inception in 1960, computer graphics (CG) technology has quickly progressed from simple 3-D models to complex, photorealistic recreations of the human face and body. Alongside this innovation, lawmakers and courts in the United States have struggled to define what is illegal, what is "obscene”, and what is protected under the First Amendment with regards to child pornography. What has emerged from this debate is that the laws surrounding child pornography hinge on whether the material in question is photographic or CG. To this end, we measure how reliable the human visual system is in distinguishing CG from photographic …

Mathematical Analysis Of Sphere Resting In The Vertex Of Right Pyramid & Polyhedron, Filleting Of The Faces & Packing Of The Spheres In The Vertex, Harish Chandra Rajpoot Rajpoot Hcr

Harish Chandra Rajpoot H.C. Rajpoot

Low-Voltage Polymer/Small-Molecule Blend Organic Thin-Film Transistors And Circuits Fabricated Via Spray Deposition, Simon Hunter, Jeremy W. Ward, Marcia M. Payne, John E. Anthony, Oana D. Jurchescu, Thomas D. Anthopoulos

Chemistry Faculty Publications

Organic thin-film electronics have long been considered an enticing candidate in achieving high-throughput manufacturing of low-power ubiquitous electronics. However, to achieve this goal, more work is required to reduce operating voltages and develop suitable mass-manufacture techniques. Here, we demonstrate low-voltage spray-cast organic thin-film transistors based on a semiconductor blend of 2,8-difluoro- 5,11-bis (triethylsilylethynyl) anthradithiophene and poly(triarylamine). Both semiconductor and dielectric films are deposited via successive spray deposition in ambient conditions (air with 40%–60% relative humidity) without any special precautions. Despite the simplicity of the deposition method, p-channel transistors with hole mobilities of >1 cm²/Vs are realized at −4 …

Identification And Doubly Robust Estimation Of Data Missing Not At Random With An Ancillary Variable, Wang Miao, Eric Tchetgen Tchetgen, Zhi Geng

Harvard University Biostatistics Working Paper Series

No abstract provided.

Update On Radiation Dose From Galactic And Solar Protons At The Moon Using The Lro/Crater Microdosimeter, J. E. Mazur, Cary Zeitlin, Nathan A. Schwadron, M. D. Looper, Lawrence W. Townsend, J. B. Blake, Harlan E. Spence

Physics & Astronomy

The NASA Lunar Reconnaissance Orbiter (LRO) has been exploring the lunar surface and radiation environment since June 2009. In Mazur et al. [2011] we discussed the first 6 months of mission data from a microdosimeter that is housed within the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument onboard LRO. The CRaTER microdosimeter is an early version of what is now a commercially available hybrid that accurately measures total ionizing radiation dose in a silicon target (http://www.teledynemicro.com/product/radiation-dosimeter). This brief report updates the transition from a deep solar minimum radiation environment to the current …

Revealing Important Nocturnal And Day-To-Day Variations In Fire Smoke Emissions Through A Multiplatform Inversion, Pablo E. Saide, David A. Peterson, Arlindo Da Silva, Bruce Anderson, Luke D. Ziemba, Glenn Diskin, Glen Sachse, Jonathan Hair, Carolyn Butler, Marta Fenn, Jose L. Jimenez, Pedro Campuzano-Jost, Anne E. Perring, Joshua P. Schwarz, Milos Z. Markovic, Phil Russell, Jens Redemann, Yohei Shinozuka, David G. Streets, Fang Yan, Jack E. Dibb, Robert Yokelson, O Brian Toon, Edward Hyer, Gregory R. Carmichael

Earth Sciences

We couple airborne, ground-based, and satellite observations; conduct regional simulations; and develop and apply an inversion technique to constrain hourly smoke emissions from the Rim Fire, the third largest observed in California, USA. Emissions constrained with multiplatform data show notable nocturnal enhancements (sometimes over a factor of 20), correlate better with daily burned area data, and are a factor of 2-4 higher than a priori estimates, highlighting the need for improved characterization of diurnal profiles and day-to-day variability when modeling extreme fires. Constraining only with satellite data results in smaller enhancements mainly due to missing retrievals near the emissions source, …

Symmetry And The Arrow Of Time In Theoretical Black Hole Astrophysics, David Garofalo

Faculty Articles

While the basic laws of physics seem time-reversal invariant, our understanding of the apparent irreversibility of the macroscopic world is well grounded in the notion of entropy. Because astrophysics deals with the largest structures in the Universe, one expects evidence there for the most pronounced entropic arrow of time. However, in recent theoretical astrophysics work it appears possible to identify constructs with time-reversal symmetry, which is puzzling in the large-scale realm especially because it involves the engines of powerful outflows in active galactic nuclei which deal with macroscopic constituents such as accretion disks, magnetic fields, and black holes. Nonetheless, the …

Supporting Adult Learners' Metacognitive Development With A Sociotechnical System, Kathryn Wozniak

College of Computing and Digital Media Dissertations

Metacognition is defined as thinking about and reflecting on one's cognitive processes. In learning contexts, strong metacognition leads to retention, academic success, and deep learning. While we know a lot about the metacognition of learners in grades K-12 and college, there are limited studies on adult learners' (24 and older) metacognitive awareness, how to support it, or the role technology can play, particularly since e-learning is quickly becoming the central mode of learning for adult learners. Thus, I have the following motivating research question: How can we support adult learners' metacognitive development in e-learning environments?

To better understand adult learners' …

Estimates Of Micro-, Nano-, And Picoplankton Contributions To Particle Export In The Northeast Pacific, B. L. Mackinson, S. B. Moran, M. W. Lomas, Gillian M. Stewart, R. P. Kelly

Publications and Research

The contributions of micro-, nano-, and picoplankton to particle export were estimated from measurements of size-fractionated particulate 234Th, organic carbon, and phytoplankton indicator pigments obtained during five cruises between 2010 and 2012 along Line P in the subarctic northeast Pacific Ocean. Sinking fluxes of particulate organic carbon (POC) and indicator pigments were calculated from 234Th;238U disequilibria and, during two cruises, measured by a sediment trap at Ocean Station Papa. POC fluxes at 100m ranged from 0.65 to 7.95 mmolm2 d1, similar in magnitude to previous results at Line P. Microplankton pigments dominate indicator pigment fluxes (averaging 6919% of total pigment …

Localized Ecological And Educational Effects Of Environmental Service-Learning In Portland, Oregon, Steven Matthew Braun

Dissertations and Theses

Environmental service-learning is an intentional educational experience(s) wherein learners engage in meaningful activities designed to serve the environment. Environmental service-learning activities vary according to their learning and service goals and include ecomanagement, persuasion, legal action, economic action and political action. The purpose of this mixed methods research was to explore the ecological and educational impacts of grades 6-12 environmental education, with special attention to environmental service-learning throughout Portland, Oregon.

Ecological impacts considered restoration and conservation outcomes of several environmental service-learning programs including plant communities, soils, litter removal and trail maintenance. Educational outcomes considered aspects of environmental literacy including locus of …

Qcri: Answer Selection For Community Question Answering - Experiment For Arabic And English, Massimo Nicosia, Simone Filice, Alberto Barron-Cedeno, Iman Saleh, Hamdy Mubarak, Wei Gao, Preslav Nakov, Giovanni Da San Martino, Alessandro Moschitti, Kareem Darwish, Lluis Marquz Marquz, Shafiq Joty, Walid Magdy Magdy

Research Collection School Of Computing and Information Systems

This paper describes QCRI’s participation in SemEval-2015 Task 3 “Answer Selection in Community Question Answering”, which targeted real-life Web forums, and was offered in both Arabic and English. We apply a supervised machine learning approach considering a manifold of features including among others word n-grams, text similarity, sentiment analysis, the presence of specific words, and the context of a comment. Our approach was the best performing one in the Arabic subtask and the third best in the two English subtasks

Consciousness-Raising, Error Correction And Proofreading., Josephine O'Brien

All Works

The paper discusses the impact of developing a consciousness-raising approach in error correction at the sentence level to improve students' proofreading ability. Learners of English in a foreign language environment often rely on translation as a composing tool and while this may act as a scaffold and provide some support, it frequently leads to predictable and persistent errors. Such fossilization can cause inaccuracies that detract from student composition and that require instruction and repeated practice in order to eradicate the errors. The current paper reports on an experiment in consciousness-raising about specific categories of errors with a group of 30 …

Variable Hard-X-Ray Emission From The Candidate Accreting Black Hole In Dwarf Galaxy Henize 2–10, Thomas J. Whalen, Ryan C. Hickox, Amy E. Reines, Jenny E. Greene

Dartmouth Scholarship

We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2–10. Recent observations suggest that this galaxy hosts an actively accreting black hole (BH) with mass ~10⁶ . The presence of an active galactic nucleus (AGN) in a low-mass starburst galaxy marks a new environment for AGNs, with implications for the processes by which "seed" BHs may form in the early universe. In this paper, we analyze four epochs of X-ray observations of Henize 2–10, to characterize the long-term behavior of its hard nuclear emission. We analyze observations with Chandra from …

Cross-Selectivity In The Catalytic Ketonization Of Carboxylic Acids, Alexey Ignatchenko, Joseph Deraddo, Vincent Marino, Adam Mercado

Chemistry Faculty/Staff Publications

A mixture of acetic and 2-methylpropanoic (isobutyric) acids representing non-branched and branched acids, respectively, was catalytically converted to a mixture of ketones in a set of statistically designed experiments (DOE). The selectivity toward the cross-ketonization product was analyzed depending on (a) temperature within 300–450 °C range, (b) molar fraction of each acid in the mixture, from 10% to 90%, and (c) liquid hourly space velocity (LHSV) within 2–12 h⁻¹, and compared against the selectivity toward two symmetrical ketones. Six metal oxide catalysts were tested and ranked on their ability to yield the cross-product as opposed to the self-condensation …

Black Carbon: Sources, Mobility And Fate In Freshwater Systems, Sasha Wagner

FIU Electronic Theses and Dissertations

Black carbon (BC) is a complex mixture of polycondensed aromatic compounds produced by the incomplete combustion of biomass during events such as wildfires and the burning of fossil fuels. Black carbon was initially considered to be a refractory form of organic matter. However, recent studies have shown that BC can be quite mobile and reactive in the terrestrial environment. Black carbon can be translocated from soils and sediments in the form of dissolved BC (DBC). A global correlation between DBC and bulk dissolved organic carbon (DOC) has been established for fluvial systems where DBC comprises approximately 10% of the total …

Investigations Of The Air-Water Interface: A Structural Analysis Of Metallic Surface Films And Aquatic Surface Films By Comparative Microscopy, Randall William Smith

Dissertations and Theses

The air-water interface is an important natural boundary layer that has been neglected as an area of environmental field research. This study establishes that comparative microscopy can be an effective environmental method, and establishes that the term metallic surface films, is a more accurate descriptor than iron oxide surface films. This research shows that surface films are complex, often with layered structure, serve as habitat for significant biota, and act as a point of mineralization to several transition metal elements including manganese, iron, copper, nickel and zinc. This study demonstrates that surface films form under several conditions and can have …

Optimization Of A Solar Simulator For Planetary-Photochemical Studies, Et-Touhami Es-Sebbar, Yves Bénilan, Nicolas Fray, Hervé Cottin, Antoine Jolly, Marie-Claire Gazeau

Dr. Et-touhami Es-sebbar

Low-temperature microwave-powered plasma based on hydrogen and hydrogen with noble gas mixtures are widely used as a continuous vacuum ultraviolet (VUV) source in laboratory experiments carried out to mimic the photochemistry in astrophysical environments. In this work, we present a study dedicated to optimizing such sources in terms of mono-chromaticity at Lyα (H(Lyα) line at 121.6 nm ~ 10.2 eV) and high spectral irradiance. We report the influence on the emission spectrum of a wide range of experimental conditions including gas composition (pure H2, pure He, and H2/He mixture), gas pressure, flow rates, and microwave power. The absolute spectral irradiance …

Learning Cooperative Games, Maria-Florina Balcan, Ariel D. Procaccia, Yair Zick

Yair Zick

This paper explores a PAC (probably approximately correct) learning model in cooperative games. Specifically, we are given m random samples of coalitions and their values, taken from some unknown cooperative game; can we predict the values of unseen coalitions? We study the PAC learnability of several well-known classes of cooperative games, such as network flow games, threshold task games, and induced subgraph games. We also establish a novel connection between PAC learnability and core stability: for games that are efficiently learnable, it is possible to find payoff divisions that are likely to be stable using a polynomial number of samples

Confocal Raman Spectroscopy And Afm For Evaluation Of Sidewalls In Type Ii Superlattice Fpas, D. A. Tenne

Physics Faculty Publications and Presentations

We propose to utilize confocal Raman spectroscopy combined with high resolution atomic force microscopy (AFM) for nondestructive characterisation of the sidewalls of etched and passivated small pixel (24 μm×24 μm) focal plane arrays (FPA) fabricated using LW/LWIR InAs/GaSb type-II strained layer superlattice (T2SL) detector material. Special high aspect ratio Si and GaAs AFM probes, with tip length of 13 μm and tip aperture less than 7°, allow characterisation of the sidewall morphology. Confocal microscopy enables imaging of the sidewall profile through optical sectioning. Raman spectra measured on etched T2SL FPA single pixels enable us to quantify the …

Fast And Sensitive Genome-Hashing Software And Its Application In Using Ngs As A Detection Agent For Bacterial Presence In Oral Metagenomic Samples, Paul Michael Gontarz

Dissertations

Next generation sequencing has increased the throughput of sequenced DNA into the range of billions of nucleotides sequenced per day. With the increased speed of DNA sequencing and the short length of reads produced by next generation sequencers, a significant challenge has been created in quickly and accurately assembling the hundreds of millions of short reads created by modern sequencing instruments into their full genomic sequences. With the increase in throughput in next generation sequencing and the decrease in time and cost to perform DNA sequencing, novel applications for DNA sequencing are being considered. Among them is a methodology by …

Temperature Dependent Surface Reconstruction Of Freely Suspended Films Of 4-N-Heptyloxybenzylidene-4-N-Heptylaniline, Daniel E. Martinez Zambrano

Lawrence University Honors Projects

Surfaces of freely suspended thick films of 4-n-heptyloxybenzylidene-4-n-heptylaniline (7O.7) in the crystalline-B phase have been imaged using non-contact mode atomic force microscopy. Steps are observed on the surface of the film with a height of 3.0 +/- 0.1 nm corresponding to the upright molecular length of 7O.7. In addition, we find that the step width varies with temperature between 56 and 59 degrees C. The steps are many times wider than the molecular length, suggesting that the steps are not on the surface but instead originate from edge dislocations in the interior. Using a strain model for liquid crystalline layers …

Tools Managing Seed Urls (Detecting Off-Topic Pages), Yasmin Alnoamany, Michele C. Weigle, Michael L. Nelson

Computer Science Presentations

PDF of a powerpoint presentation from the Columbia University Web Archiving Collaboration: New Tools and Models Conference, in New York, New York, June 4-5, 2015. Also available on Slideshare.

Field Line Distribution Of Mass Density At Geostationary Orbit, Richard Denton, Kazue Takahashi, Jimyoung Lee, C.K. Zeitler, N.T. Wimer, E. Litscher, H.J. Singer, Kyungguk Min

Dartmouth Scholarship

The distribution of mass density along the field lines affects the ratios of toroidal (azimuthally oscillating) Alfv'{e}n frequencies, and given the ratios of these frequencies we can get information about that distribution. Here we assume the commonly used power law form for the field line distribution, rho_{m} = rho_{m,eq} ( L R_{E} /R )^alpha, where rho_{m,eq} is the value of the mass density rho_{m} at the magnetic equator, L is the L shell, R_{E} is the Earth's radius, R is the geocentric distance to a point on the field line, and alpha is the power law coefficient. Positive values of …

Radioprotective Effect Of Vitamin C (L-Ascorbic Acid) And Some Myriad Enzymes, Nkiru F. Opara Jarlath

Nkiru Opara

It is observed that vitamin C has similar structure with that of melatonin, from chemistry point of view compounds of similar structure has the same chemical properties but different physical properties. This is a research on the radioprotective effect of vitamin C / glutathione and some free radical scavengers. Radiation in human body is a process where energy emitted by one body travels in a straight line through a medium or through space. It is energy in the form of particles or waves. It is emitted naturally in sunlight and is also made by man for use in X-rays, cancer …

Mathematical Models Of Games Of Chance: Epistemological Taxonomy And Potential In Problem-Gambling Research, Catalin Barboianu

UNLV Gaming Research & Review Journal

Games of chance are developed in their physical consumer-ready form on the basis of mathematical models, which stand as the premises of their existence and represent their physical processes. There is a prevalence of statistical and probabilistic models in the interest of all parties involved in the study of gambling – researchers, game producers and operators, and players – while functional models are of interest more to math-inclined players than problem-gambling researchers. In this paper I present a structural analysis of the knowledge attached to mathematical models of games of chance and the act of mathematical modeling, arguing that such …

Predicting Invasion Rates For Phragmites Australis, Rachel Nydegger, Jacob Duncan, James A. Powell

Jacob P Duncan

In wetlands of Utah and southern Idaho as well as estuaries of the east coast, the ten-foot tall invasive grass Phragmites australis can be found near waterways, where it outcompetes native plants and degrades wildlife habitat. Phragmites australis is an obligate out-crossing plant that can spread sexually through seed disper- sal, or asexually via stolons and rhi- zomes (Kettenring and Mock 2012). Small patches are usually a single genetic individual, spreading vegetatively (and slowly) via runners; when patches become genetically diverse viable seeds are produced and invasion rates can be increase by an order of magnitude (Kettenring et al. 2011)