Physical Sciences and Mathematics Commons^™

The Effect Of Nonlinear Propagation On Near-Field Acoustical Holography, Micah Raymond Shepherd

Theses and Dissertations

Near-field acoustical holography (NAH) has been used extensively for acoustical imaging of infinitesimal-amplitude (or small-amplitude) sources. However, recent interests are in the application of NAH to image finite-amplitude (or high-amplitude) sources such as jets and rockets. Since NAH is based on linear equations and finite-amplitude sources imply nonlinear effects, which cause shock formation and consequently an altered spectral shape, a feasibility study is carried out to determine the effect of nonlinear propagation on NAH. Jet and rocket sources typically have a distinct spectral shape resembling a ‘haystack’ and center frequencies varying from 30 to 300 Hz. To test the effect …

Effectively Combining Independent 2 X 2 Tables For Valid Inferences In Meta Analysis With All Available Data But No Artificial Continuity Corrections For Studies With Zero Events And Its Application To The Analysis Of Rosiglitazone's Cardiovascular Disease Related Event Data, Lu Tian, Tianxi Cai, Nikita Piankov, Pierre-Yves Cremieux, L. J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.

Quantum Dot Resonant Tunneling Diode For Telecommunication Wavelength Single Photon Detection, H. W. Li, B. E. Kardynał, P. See, A. J. Shields, P. Simmonds, H. E. Beere, D. A. Ritchie

Paul J. Simmonds

The authors present a quantum dot (QD) based single photon detector operating at a fiber optic telecommunication wavelength. The detector is based on an AlAs/In_0.53Ga_0.47As/AlAs double-barrier resonant tunneling diode containing a layer of self-assembled InAs QDs grown on an InP substrate. The device shows an internal efficiency of about 6.3% with a dark count rate of 1.58 × 10⁻⁶ ns⁻¹ for 1310 nm photons.

The Use Of Non-Natural Nucleotides To Probe Template-Independent Dna Synthesis, Anthony J. Berdis, David Mccutcheon

Chemistry Faculty Publications

The vast majority of DNA polymerases use the complementary templating strand of DNA to guide each nucleotide incorporation. There are instances, however, in which polymerases can efficiently incorporate nucleotides in the absence of templating information. This process, known as translesion DNA synthesis, can alter the proper genetic code of an organism. To further elucidate the mechanism of template-independent DNA synthesis, we monitored the incorporation of various nucleotides at the “blunt-end” of duplex DNA by the high-fidelity bacteriophage T4 DNA polymerase. Although natural nucleotides are not incorporated at the blunt-end, a limited subset of non-natural indolyl analogues containing extensive π-electron surface …

Spotmac: A Pencil-Beam Mac For Wireless Mesh Networks, K. Chin

Faculty of Informatics - Papers (Archive)

Deafness is a key problem. It erodes the performance gains provided by directional antennas, and introduces a new hidden terminal problem. To address deafness, and hence the hidden terminal problem, we propose SpotMAC. By exploiting narrow or pencil beams, SpotMAC achieves high spatial reuse, throughput and fairness. In addition, pencil beams simplify the collision avoidance process and constrain the hidden terminal problem to a linear topology which can be solved using an inverse RTS/CTS exchange. From extensive simulation studies, we confirm nodes using SpotMAC have several orders of magnitude higher throughput than those using the IEEE 802.11 MAC with omni-directional …

On The Suitability Of Framed Slotted Aloha Based Rfid Anti-Collision Protocols For Use In Rfid-Enhanced Wsns, Dheeraj Klair, K. Chin, R. Raad

Faculty of Informatics - Papers (Archive)

This paper studies the energy consumption of frame slotted Aloha (FSA) based anti-collision protocols. Specifically, we investigate twelve FSA variants using a detailed qualitative and quantitative methodology to evaluate efficiency with varying tag population. Our results show that the variant that adjusts its frame size in accordance with tag population and incorporates the muting and early-end feature has the lowest energy consumption, hence most suited for RFID-enhanced WSNs.

Gis Aided Archaeological Research Of El Camino Real De Los Tejas With Focus On The Landscape And River Crossings Along El Camino Carretera., Jeffrey M. Williams

Faculty Publications

Many generations of indigenous pathways through the forests of eastern Texas have their origins obscured in antiquity. Utilized by early European explorers, these pathways became modified through heavy use and the expansions and improvements needed to accommodate easy passage of European horses and carts and finally the heavy wagons of Anglo-American settlers. The first road through Texas, El Camino Real de Los Tejas, utilized portions of these early trails.

El Camino Carretera (known as the cart road) is an early segment of El Camino Real de los Tejas that crossed the Sabine River at the boundary between Texas and Louisiana. …

Monsters In The Cosmic Sea: Black Holes And Einstein's Astrophysical Legacy, Shane L. Larson

Public Talks

No abstract provided.

Persistence And Memory In Patchwork Dynamics For Glassy Models, Alan Middleton, Creighton K. Thomas, Olivia L. White

Physics - All Scholarship

Slow dynamics in disordered materials prohibits direct simulation of their rich nonequilibrium behavior at large scales. "Patchwork dynamics" is introduced to mimic relaxation over a very broad range of time scales by equilibrating or optimizing directly on successive length scales. This dynamics is used to study coarsening and to replicate memory effects for spin glasses and random ferromagnets. It is also used to find, with high confidence, exact ground states in large or toroidal samples.

Search For Third-Generation Scalar Leptoquarks In Pp̅ Collisions At √S = 1.96 Tev, V. M. Abazov, Kenneth A. Bloom, Gregory R. Snow, D0 Collaboration

Kenneth Bloom Publications

We report on a search for charge-1/3 third-generation leptoquarks (LQ) produced in pp̅ collisions at √s = 1.96 TeV using the D0 detector at Fermilab. Third-generation leptoquarks are assumed to be produced in pairs and to decay to a tau neutrino and a b quark with branching fraction B. We place upper limits on (pp̅→ LQ L̅Q̅) B² as a function of the leptoquark mass M_LQ. Assuming B^-1, we exclude at the 95% confidence level third-generation scalar leptoquarks with M_LQ < 229 GeV.

Interview With Anthony Boutard, Ayers Creek Farm, 2007 (Audio), Anthony Boutard

All Sustainability History Project Oral Histories

Interview of Anthony Boutard by Magda Gaytan at Ayers Creek Farm on August 10th, 2007.

The interview index is available for download.

Interview With Dan J. Wilson, Sudan Farms, 2007 (Audio), Dan J. Wilson

All Sustainability History Project Oral Histories

Interview of Dan J. Wilson by Jason Keaton at Canby, Oregon on August 10th, 2007.

The interview index is available for download.

Oases In The Dark: Galaxies As Probes Of The Cosmos, Shane L. Larson

Public Talks

No abstract provided.

Mixing And Homogenization In The Early Solar System: Clues From Sr, Ba, Nd, And Sm Isotopes In Meteorites, Rasmus Andreasen, Mukul Sharma

Dartmouth Scholarship

High-precision barium isotopic compositions of large samples of an ordinary chondrite and a eucrite are identical to the terrestrial values. In contrast, the carbonaceous chondrites reveal excesses in ¹³⁵Ba and ¹³⁷Ba of around +39 and +22 parts per million (ppm), respectively; no anomalies are resolvable in ^130,132,138Ba. High-precision Sr isotopic compositions of all meteorites are identical within error. The data are consistent with the carbonaceous chondrites having an excess in the r-process ^135,137Ba with respect to Earth, eucrite parent bodies, and ordinary chondrites. The carbonaceous chondrites, however, display no variation in the r- and …

Hard/Soft-Acid/Base Principle And The Reaction Ahbs+Asbh → Ahbh+Asbs, Jerry Goodisman

Chemistry - All Scholarship

A demonstration of the hard/soft-acid/base principle involves showing that the energy change for Ah Bs + As Bh → Ah Bh + As Bs is always negative. We point out problems with assumptions made about hardness and strength of the components, but emphasize that problems with the way in which energies are calculated are even more important.

Bioanalyze: A Tool For The Simulation And Analysis Of Biological Systems, James Norman

All Theses

Scientists have turned to a more systemic approach to biology in order to fully understand the complex functionality of living organisms. Biologist and Geneticist have compiled an impressive amount of experimental data for a multitude of biological systems. Modeling and simulation of these systems has become a prominent tool in the field of Systems Biology. In this paper we present a review of General Systems Theory, Systems Biology, and introduce BioAnalyze. BioAnalyze is a web application designed to simulate, and analyze, the functional dynamics of biological systems.

An Efficient Asynchronous Peer To Peer Auction Using Yao Oblivious Transfer, Charles Lobo

All Theses

Distributed electronic auctions are increasingly preferred over centralized electronic auctions today. The success of peer-to-peer file sharing networks has made distributed electronic auctions a possibility. Due to trust and conflict of interest issues with centralized auctioneer systems, multiple auctioneers in distributed roles are preferred. However, there is a possibility of auctioneer node collusion [16] and auctioneer-bidder collusion and auctioneer-seller collusion in such mechanisms.
To overcome these problems, a new peer-to-peer auction protocol [17] with auctioneers forming auctioneer groups has been proposed. This protocol keeps the auctioneers honest by ensuring that no single auctioneer in the group has absolute control over …

A Comparative Study On Ontology Generation And Text Clustering Using Vsm, Lsi, And Document Ontology Models, William Taylor

All Theses

Although using ontologies to assist information retrieval and text document processing has recently attracted more and more attention, existing ontology-based approaches have not shown advantages over the traditional keywords-based Latent Semantic Indexing (LSI) method. This paper proposes an algorithm to extract a concept forest (CF) from a document with the assistance of a natural language ontology, the WordNet lexical database. Using concept forests to represent the semantics of text documents, the semantic similarities of these documents are then measured as the commonalities of their concept forests. Performance studies of text document clustering based on different document similarity measurement methods show …

Topology-Aware Transmission Scheduling For Distributed Highway Traffic Monitoring Wireless Sensor Networks, Devang Bagaria

All Theses

Wireless sensor networks have been deployed along highways for traffic monitoring. The thesis studies a set of transmission scheduling methods for optimizing network throughput, message transfer delay, and energy efficiency. Today's traffic monitoring systems are centrally managed. Several studies have envisioned the advantages of distributed traffic management techniques. The thesis is based on previously proposed hierarchical sensor network architecture, for which the routing and transmission scheduling methods are derived.
Wireless sensor networks have a lifetime limited by battery energy of the sensors. The thesis proposes to assign schedules for nodes to transmit and receive packets and turning off their radios …

Performance Of Voip Services On A Docsis Network Targeted By A Denial Of Service Attack, Benjamin Sangster

All Theses

Over 48 million end users worldwide utilize cable modems as their means of accessing the Internet at high speeds. The United States accounts for 54% of those users. Networks which provide access via cable modems utilize Data Over Cable Service Interface Specifications (DOCSIS) as their means of network management. As availability to the Internet increases (especially at high speeds supported by broadband access), so does the opportunity for malicious activity against users utilizing the Internet. Denial-of-service (DoS) attacks are one form of malicious activity and one of the most common. In commonplace Ethernet-based wired networks, a DoS attack requires relatively …

Responses Of Problematic Cyanobacteria To Exposures Of Copper Containing Algaecides, O'Niell Tedrow

All Theses

Cyanobacteria (blue-green algae) are associated with production of potent hepatotoxins (Microcystis; microcystin) and dense surface and benthic mats (Lyngbya), which impede critical water resource usages. Water resource managers are in need of effective and efficient treatment techniques for these problematic algae in field situations. Applications of algaecides are considered in situations where algal problems become acute or when critical water usages are threatened. However, laboratory data are needed that accurately predict responses of algae prior to field-scale algaecide applications. Site water and algae were used in laboratory algal toxicity experiments to predict responses of the target alga following an algaecide …

A Comparison Of Class Diagram Construction At Three Different Phases Of Compilation, Robert Bailey Iii

All Theses

In maintaining, designing, and testing of OO systems, understanding the relationships between the classes and corresponding objects is imperative. Class diagrams provide program visualization that promotes easier understanding of large systems. Class diagrams are especially helpful when systems become too large to conceptualize without automated graphical illustration. There are many tools available to software developers that permit generation of class diagrams for large scale computing applications, many of which use various parsing approaches to extract information for a class diagram. In this paper, we compare and evaluate three tools that extract information for class diagrams from different phases of the …

Carbon Nanomaterials In Biological Systems, Sijie Lin

All Theses

ABSTRACT


This thesis intends to present, from the biophysical viewpoint, my study on understanding carbon nanomaterials in biological and environmental systems. Carbon nanotubes and fullerenes represent a major family of carbon nanoparticles which possess distinct electrical, optical and mechanical properties. However, the major hurdle for making carbon nanomaterials bioavailable lies in their tendency toward bundling, driven by hydrophobic interaction, van der Waals force, and pi-stacking. To overcome this problem, we used non-covalent binding of zwitterionic lysophopholipids (LPL) onto the external surfaces of single-walled carbon nanotubes (SWNTs). This method affords superior SWNT solubility in aqueous solution. The stability of SWNT-LPL complex …

On Inter-Referential Awareness In Collaborative Augmented Reality, Jeffrey William Chastine

Computer Science Dissertations

For successful collaboration to occur, a workspace must support inter-referential awareness - or the ability for one participant to refer to a set of artifacts in the environment, and for that reference to be correctly interpreted by others. While referring to objects in our everyday environment is a straight-forward task, the non-tangible nature of digital artifacts presents us with new interaction challenges. Augmented reality (AR) is inextricably linked to the physical world, and it is natural to believe that the re-integration of physical artifacts into the workspace makes referencing tasks easier; however, we find that these environments combine the referencing …

C-2/C-3 Annulation And C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Ming Yu, Hongda Zhao, Brian L Pagenkopf

Chemistry Publications

The annulation reaction between various indoles and 2-alkoxycyclopropanoate esters is reported. Both high efficiency and complete stereochemical control were observed in some cases with this annulation process. A single stereocenter on the cyclopropane controls the diastereoselective formation of up to four new stereocenters. A different reaction course was observed with 3-substituted indole substrates, and an intervening C-3 to C-2-migration process arose that gives synthetically useful C-2 alkylation indole products.

The Yale Lar Tpc, Mitchell Soderberg, A. Curioni, Bonnie T. Fleming

Physics - All Scholarship

In this paper we give a concise description of a liquid argon time projection chamber (LAr TPC) developed at Yale, and present results from its first calibration run with cosmic rays.

Strain-Induced Formation Of Carbon And Boron Clusters In Boron Carbide During Dynamic Indentation, Dipankar Ghosh, Ghatu Subhash, Chee Huei Lee, Yoke Khin Yap

Department of Physics Publications

The authors found that the level of amorphization or structural disorder in boron carbide is higher when induced by dynamic indentation compared to static indentation. Visible and uv Raman spectroscopies indicate that sp²-bonded aromatic carbon clusters were formed, consistent with the detected photoluminescence spectra. Infrared absorption shows that amorphous boron clusters were created by dynamic indentation which has strain rates ∼10⁸ order higher than that introduced by static indentation. The decreased intensity of infrared stretching mode of carbon-boron-carbon (CBC) chains also suggests that amorphization is due to the collapse of B₁₁C(CBC) unit cells, which reorganize …

An Optimal Solution On Screening And Treatment Of Chlamydia Trachomatis And Neisseria Gonorrhoeae, Xin Wei

Mathematics Theses

We propose a resource allocation model for the management of the fund for the screening and treatment of women infected by Chlamydia trachomatis and Neisseria gonorrhoeae. The goal is to maximize the number of infected women cured of Chlamydia trachomatis and Neisseria gonorrhoeae infections. The population going for screening is divided into groups by ages and races. The group number is dynamic. Dierent groups have dierent infection rates. There are four possible test assays and four possible treatments. We employed a two-phase algorithm to solve the problem. The first phase is small so an exhaustive method is applied, while the …

Interview With Trevor Baird, Baird Family Orchard, 2007 (Audio), Trevor Baird

All Sustainability History Project Oral Histories

Interview of Trevor Baird by Adam Hopfe at Portland State University on August 7th, 2007.

The interview index is available for download.

Inspection And Characterization Of Exoplanet Using The Chara Array, Ellyn K. Baines

Physics and Astronomy Dissertations

Until the last decade or so, our entire knowledge of planets around Sun-like stars consisted of those in our own Solar System. This is no longer the case. Over 200 planets have been discovered through radial velocity surveys and photometric studies, both of which depend on observing the planet's effects on its host star. Much of our knowledge of the planets orbiting these stars is uncertain, based on assumptions about the stars' masses and the planets' orbital inclinations. This dissertation is comprised of two main sections. The first involves measuring the angular diameters for a sample of exoplanet host stars …