Physical Sciences and Mathematics Commons^™

Numerical Investigations On The Formation Of Tropical Storm Debby During Namma-06, Sen Chiao, Gregory S. Jenkins

Ocean Engineering and Marine Sciences Faculty Publications

Mesoscale model forecasts were carried out beginning at 0000 UTC 19 August for simulating Tropical Disturbance 4, which was named Tropical Storm Debby on 22 August 2006. The Weather Research and Forecasting model, with 25-km grid spacing and an inner nested domain of 5-km grid spacing, was used. The development of a small closed vortex at approximately 0600UTC20 August 2006 at 850 hPa was found off the coast of Guinea in agreement with satellite images in the 5-km simulation. Intense convection offshore and over the Guinea Highlands during the morning of 20 August 2006 led to the production of a …

Evaluation Of Data Reduction Algorithms For Real-Time Analysis, Steven M. Lazarus, Michael E. Splitt, Michael D. Lueken, Rahul Ramachandran, Xiang Li, Sunil Movva, Sara J. Graves, Bradley T. Zavodsky

Ocean Engineering and Marine Sciences Faculty Publications

Data reduction tools are developed and evaluated using a data analysis framework. Simple (nonadaptive) and intelligent (adaptive) thinning algorithms are applied to both synthetic and real data and the thinned datasets are ingested into an analysis system. The approach is motivated by the desire to better represent highimpact weather features (e.g., fronts, jets, cyclones, etc.) that are often poorly resolved in coarse-resolution forecast models and to efficiently generate a set of initial conditions that best describes the current state of the atmosphere. As a precursor to real-data applications, the algorithms are applied to one- and two-dimensional synthetic datasets. Information gleaned …

Greening The Green Revolution: Moving Beyond Chemicals To Sustainable Agricultural Practices, Elizabeth G. Crawley

Electronic Theses and Dissertations

Agriculture has dominated the economy of many developing countries for centuries, which has led to development policies that center on agricultural development. An obvious approach to improved production is to decrease agricultural losses in the fields and increase efficiency to markets. This study focuses on the developmental role of pesticides and chemical fertilizers on non-traditional agricultural export farming and the adoption of IPM techniques. With farmers in the Comayagua Valley of Honduras, an Asian vegetable production center for the country, as the study population, the costs and benefits of planting oriental vegetables was examined. Statistical analysis was used to examine …

Spinning Tubes: An Authentic Research Experience In A Three-Hour Laboratory, Arnold E. Sikkema, Steven D. Steenwyk, John W. Zwart

University Faculty Publications and Creative Works

We discuss a three-hour laboratory that is a microcosm of physics research, starting with the discovery of an intriguing phenomenon, and including participation in "research conferences" and the interplay of theory and experiment. Students are given a small segment of PVC pipe marked at opposite ends with different symbols and asked to observe what happens when the pipe is placed on a horizontal surface and one end is pushed downward by a finger to initiate a rotation. Most students immediately recognize that the symbol at one end is visible while the other is not, and set about trying to understand …

Topological Susceptibility With The Asqtad Action, James E. Hetrick, A. Bazavov

All Faculty Articles - School of Engineering and Computer Science

Chiral perturbation theory predicts that in quantum chromodynamics (QCD), light dynamical quarks suppress the gauge-field topological susceptibility of the vacuum. The degree of suppression depends on quark multiplicity and masses. It provides a strong consistency test for fermion formulations in lattice QCD. Such tests are especially important for staggered fermion formulations that lack a full chiral symmetry and use the "fourth-root" procedure to achieve the desired number of sea quarks. Over the past few years we have measured the topological susceptibility on a large database of 18 gauge field ensembles, generated in the presence of 2+1 flavors of dynamical asqtad …

Information Risk And Underwriter Switching In Seos: Evidence From China, Wei Luo, Pingui Rao, Heng Yue

Research Collection School Of Accountancy

In this paper we examine whether information risk affects underwriter switching in a seasoned equity offering (SEO) process. Building on previous research, we hypothesize that SEO firms and underwriters associate with one another by mutual choice, and firms with a low degree of information risk tend to match up with prestigious underwriters. Using a sample of SEO firms in China and employing accruals quality as a proxy of information risk, we find evidence consistent with our hypothesis: the information risk and the initial public offering (IPO) underwriters’ reputation at the time of the SEO jointly determine the probability that the …

Optical Coherence: Recreation Of The Experiment Of Thompson And Wolf, David Collins

Physics

The purpose of our experiment is to recreate the experiment done by Thompson and Wolf in 1957 on the measurement of optical coherence. What is novel about our approach is that it allows one to view the effects of source size on optical spatial coherence in real time.

Design And Construction Of A Thermal Diffusion Cloud Chamber, Alexander Donoghue

Physics

This paper will cover the theory behind a thermal diffusion cloud chamber. In addition to that it will cover the process, thought and material used to construct two different cloud chambers. It will also discuss the effects of materials used in each chamber on the working of the chamber.

Determining Pulsation Period For An Rr Lyrae Star, Leah M. Fabrizio

Physics

No abstract provided.

Cryogenic Refrigeration For Quantum Voltage Standards, Jeffrey Power

Physics

Currently the world maintains the voltage standard using a Josephson junction which makes use of the properties of superconductors and quantum tunneling. Current technology requires liquid He to cool the Josephson junctions to ~4 K to allow them to function as superconductors. He (l) is expensive and price is geographically dependent. Here we investigated using a cryocooler, modeled after a Gifford-McMahon Refrigerator, that could run on 120V (or a standard outlet) and used gaseous He as the working fluid –a less geographically dependent and inexpensive alternative to He (l). We found that indeed a standard outlet gaseous He compressor could …

Survey Of Meteorite Samples For 92nb, 98tc, And 60fe Using Gamma Ray Spectroscopy, Robert Maxwell

Physics

The focus of this senior project was the use of gamma ray spectroscopy to survey meteorite samples for 92Nb, 98Tc, and 60Fe. The presence of measurable amounts of 26Al (half-life 717,000 years) in meteorites leads astrophysists to believe that 92Nb, 98Tc, and 60Fe should also be present in detectable amounts, though they have not yet been conclusively found. Since the isotopes that were looked for in this senior project are not long lived in comparison to the age of the solar system, their presumed presence indicates that they are continuously being made in outer space and deposited on space objects.

Investigation Of Track-Cluster Matching Vs Track-Cell Matching In The Alice Detector At Cern, Kevin Coulombe

Physics

The ALICE (A Large Ion Collider Experiment) Experiment is a detector that is one of four stationed at the CERN Large Hadron Collider. The goal of ALICE is to investigate the properties of the quark-gluon plasma, a new form of matter which only existed during the first microsecond of the Universe. ALICE measures the aftermath of the collision of two lead ions. Some information detected is the trajectory of the particles traveling through the tracking detectors and energy deposited in the calorimeters. Both the tracks and energy are required to determine the identities of the various particles as they travel …

Analysis Of The Blazar 1es1218+30.4, Timothy Wolf

Physics

I analyzed the Blazar 1ES1218+30.4 in the high energy spectrum with VERITAS telescope data. The analysis used improved the energy spectrum obtained for the blazar from a maximum of 2.49 TeV to 3.85 TeV. The flux for this point is greater than the previous fit equation predicts, indicating a possible shoulder in the EBL, or Extragalactic Background Light.

Experiments On De Vries Liquid Crystals: A Software Approach, Austin Havens

Physics

This paper describes two programs I developed to facilitate the study of liquid crystals. The first program is a graphical user interface to increase the accuracy of the birefringence measurements , which relates to their orientational order, by using a camera. The second program was designed to help study the effects of time varying fields on liquid crystals by matching data from a recorded video to oscilloscope data in order to attach data from image analysis to the voltage applied to the cell.

Study Of Accretion Effects Of Transients In Lmxb System, Quentin Lamicq

Physics

Neutron stars are intriguing stellar laboratories that are very exciting to study due to the presence of matter in an extreme state. The luminosity of some neutron star transients in low mass X-ray binary (LMXB) systems is known to have quiescent intervals that may be affected by the rate and duration of accretion from the companion star onto the neutron star. We refined a model of the luminosity of the neutron star to allow for possibility that the accretion rate declines at a steady rate until it reaches zero. After a neutron star goes through an outburst, the quiescent period …

Resistance Of The Superconducting Material Ybco, Christopher Safranski

Physics

No abstract provided.

Identification Of Bottom Quark Jets In Pb+Pb Collisions In Alice At The Lhc, Brandon Boswell

Physics

In the near future, the Large Hadron Collider (LHC) will begin colliding lead ions together with energies high enough to produce a state of matter known as the Quark-Gluon Plasma (QGP). Simulations have shown that Bottom-quark-jets (B-jets) are expected to be produced in these collisions, and that these B-jets provide a useful probe into the nature of the QGP. The ALICE detector (A Large Ion Collider Experiment) at the LHC is designed to study the nature of the QGP. In this paper we investigate the effect of requiring that an electron be inside observed jets and how this improves the …

The Usage Of Smartphones In The Calculation Of Relativistic Time Dilation Effects At Meager Velocities, Leland Gregory

Physics

The theories of special and general relativity postulate that events are not simultaneous for different observers, and that different observer's times tick at different rates depending on relative velocity and the magnitude of the gravitational field they are in. This project seeks to design a program for use with smartphones that will calculate this change in time, in real time, and keep track of the discrepancies in time experienced between the observer and a stationary point on the surface of the earth.

A New Technique For Detecting Cosmic Strings In The Cosmos Survey Using Shapelet Decomposition, Kevin A. James

Physics

The Hubble Space Telescope Treasury Program images collected as part of the Cosmic Evolution Survey were used to develop a new technique for identifying gravitational lensing events resulting from a less-massive cosmic string. By employing Monte Carlo simulations of cosmic strings embedded within the survey, galaxies were decomposed using Hermite Polynomial shapelets, and compared with the unaltered survey. An efficient set of cuts were determined for identifying a cosmic string in shapelet space. The sensitivity of the new methodology was found to be superior at detecting low-mass cosmic strings than previous methods.

Search For Dark Matter Annihilation In M5, Daniel Jackson

Physics

We analyzed the Messier 5 (M5) globular cluster for dark matter annihilation using data from VERITAS (Very Energetic Radiation Imaging Telescope Array System) to improve the flux upper limit previously done by Michael McCutecheon. We used updated software and lower energy thresholds. VERITAS consists of four ground-based gamma-ray telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. Thirty-five 20 minute observations of M5 from VERITAS are used in our analysis. The observations were collected from February to March in 2009, for a total exposure time of 10.63 hours. Gamma-rays from dark matter annihilation were not found,
but better …

Non-Convexity Of The Dimension Function For Sierpinski Pedal Triangles, Jiu Ding, Yifa Tang

Faculty Publications

We disprove the conjecture of the paper by Zhang et al.(1) on the Schur-convexity of the dimension function for the family of Sierpinski pedal triangles. We also show that this function is not convex and the related area-ratio function is not concave in their respective domain.

A Comparison Of Methods For Determining Significant Wave Heights-Applied To A 3-M Discus Buoy During Hurricane Katrina, Leslie C. Bender Iii, Norman Guinasso, John N. Walpert, Stephan D. Howden

Faculty Publications

In August 2005, the eye of Hurricane Katrina passed 90 km to the west of a 3-m discus buoy deployed in the Mississippi Sound and operated by the Central Gulf of Mexico Ocean Observing System (CenGOOS). The buoy motions were measured with a strapped-down, 6 degrees of freedom accelerometer, a three-axis magnetometer, and from the displacement of a GPS antenna measured by postprocessed-kinematic GPS. Recognizing that an accelerometer experiences a large offset due to gravity, the authors investigated four different means of computing wave heights. In the most widely used method for a buoy with a strapped-down, 1D accelerometer, wave …

Emergency Department Staff Adherence To Bad News Delivery Recommendations, Kristen R. Myers

Loma Linda University Electronic Theses, Dissertations & Projects

Emergency department (ED) staff is responsible for giving bad news regarding death, diagnoses, and other traumatic losses to patients and loved ones. Individuals receiving traumatic and sudden bad news are at increased risk of serious psychological and physiological consequences of disrupted grief. Despite published recommended practices for providers to help prevent maladaptive grief responses, little research is available on actual bad news delivery practices and factors promoting or hindering adherence to recommendations, and no study specifically explored the ED context.

The study used a qualitative design to explore bad news delivery practices, awareness of recommendations, factors perceived to hinder or …

Predictive Yasir: High Security With Lower Latency In Legacy Scada, Rouslan V. Solomakhin

Dartmouth College Master’s Theses

Message authentication with low latency is necessary to ensure secure operations in legacy industrial control networks, such as power grid networks. Previous authentication solutions by our lab and others looked at single messages and incurred noticeable latency. To reduce this latency, we develop Predictive YASIR, a bump-in-the-wire device that looks at broader patterns of messages. The device (1) predicts the incoming plaintext based on previous observations; (2) compresses, encrypts, and authenticates data online; and (3) pre-sends a part of ciphertext before receiving the whole plaintext. I demonstrate the performance properties of this approach by implementing it in the Scalable Simulation …

Evaluating Captive-Breeding Techniques And Reintroduction Success Of The California Condor (Gymnogyps Californianus), Amy C. Utt

Loma Linda University Electronic Theses, Dissertations & Projects

In this dissertation, I present two original research studies on the behavior and survival of the critically endangered California Condor (Gymnogyps californianus). I also provide a comprehensive review of the role of captive-rearing to the conservation of birds.

The first study examined the behavioral differences of puppet- and parent-reared condor juveniles reared in captivity. This study further defined and examined the behaviors of adult conspecific mentors and their interactions with juveniles. Dominance hierarchy analyses for two cohorts of juveniles and their adult mentors indicated the establishment of a linear hierarchy. Although puppet-reared juveniles engaged in fewer social behaviors in …

Designing The Dynamics Of Service Innovations, Arcot Desai Narasimhalu

Research Collection School Of Computing and Information Systems

There is no serious tool available to design service innovations even as it is gaining in important attention from the academic and industrial worlds. This paper presents a method that is specifically developed to help service innovators plan and design their innovations. The method recognizes the dependencies that exist across a service provider, customers and suppliers and help identify potential inconsistencies in the design of service innovations.

Fast Placement And Floorplanning Methods In Modern Reconfigurable Fpgas., Pritha Baneerjee Dr.

Doctoral Theses

FPGA Field-programmable gate-arrays (FPGA) are programmable hardware platforms with pre-fabricated logic and interconnects, which are electrically programmed by the user to realize a variety of circuits frequently required in a wide range of applications. Unlike application-specific integrated-circuits (ASICs), where realization of a circuit design takes several man-hours and enormous effort, the pre-fabricated logic and interconnects can be quickly programmed according to the design specification and made functional. Thus, in contrast to the ASICs, FPGAs can be customized and reconfigured depending on the need of the user. A basic FPGA chip consists of a set of configurable logic blocks (CLB) and …

Player Performance Prediction In Massively Multiplayer Online Role-Playing Games (Mmorpgs), Kyong Jin Shim, Richa Sharan, Jaideep Srivastava

Research Collection School Of Computing and Information Systems

In this study, we propose a comprehensive performance management tool for measuring and reporting operational activities of game players. This study uses performance data of game players in EverQuest II, a popular MMORPG developed by Sony Online Entertainment, to build performance prediction models forgame players. The prediction models provide a projection of player’s future performance based on his past performance, which is expected to be a useful addition to existing player performance monitoring tools. First, we show that variations of PECOTA [2] and MARCEL [3], two most popular baseball home run prediction methods, can be used for game player performance …

Weakly-Supervised Hashing In Kernel Space, Yadong Mu, Jialie Shen, Shuicheng Yan

Research Collection School Of Computing and Information Systems

The explosive growth of the vision data motivates the recent studies on efficient data indexing methods such as locality-sensitive hashing (LSH). Most existing approaches perform hashing in an unsupervised way. In this paper we move one step forward and propose a supervised hashing method, i.e., the LAbel-regularized Max-margin Partition (LAMP) algorithm. The proposed method generates hash functions in weakly-supervised setting, where a small portion of sample pairs are manually labeled to be “similar” or “dissimilar”. We formulate the task as a Constrained Convex-Concave Procedure (CCCP), which can be relaxed into a series of convex sub-problems solvable with efficient Quadratic-Program (QP). …

A Critical Constructionist View Of "At-Risk" Youth In Alternative Education, Rachelle Silverstein Touzard

Loma Linda University Electronic Theses, Dissertations & Projects

Family therapists and school counselors are increasingly called upon to provide services for youth in alternative education (Carver, Lewis, & Tice, 2010). Alternative education systems are programs for youth who have been defined as at risk. This study explored the at-risk discourse and asked the questions (a) how do youth and staff define the term at risk, (b) construct their experience in alternative education systems, and (c) experience their relationships with each other.

Combined elements from critical theory and a social constructionist perspective guided this study. A qualitative, grounded theory method was used that included semi structured interviews with …