Sociolinguistic differences between Japanese and English

posterThis poster discusses the sociolinguistic differences between Japanese and English as seen through English translations of manga and how this may impact the learning of a Japanese language learner

Efficacy of reduced order source terms for a coupled wave-circulation model in the Gulf of Mexico

A study is conducted that focuses on the trade-off between run time and accuracy of using reduced order source terms in a coupled wave-circulation model. In the study, ADCIRC+SWAN is used to model Hurricane Ike and Hurricane Ida. Water levels from the coupled model are compared to gauge data and significant wave height, peak period, and mean wave direction are compared to buoys. Results show potential for efficacy of reduced order source terms in order to eliminate computational cost while sacrificing minimal accuracy with respect to field measurements

WAVEx: Stabilized Finite Elements for Spectral Wind Wave Models Using FEniCSx

Several potential FEM discretizations of the Wave Action Balance Equation are discussed. The methods, which include streamline upwind Petrov-Galerkin (SUPG), least squares, and discontinuous Galerkin, are implemented using the open source finite element library FEniCSx for simplified 2-D cases. Open source finite element libraries, such as FEniCSx, typically only support geometries up to dimension of 3. The Wave Action Balance Equation is 4 dimensions in space so this presents difficulties. A method to use a FEM library, such as FEniCSx, to solve problems in domains with dimension larger than 4 using the product basis is discussed. A new spectral wind wave model, WAVEx, is formulated and implemented using the new finite element library FEniCSx. WAVEx is designed to allow for construction of multiple FEM discretizations with relatively small modifications in the Python code base. An example implementation is then demonstrated with WAVEx using continuous finite elements and SUPG stabilization in geographic/spectral space. For propagation in time, a generalized one step implicit finite difference method is used. When source terms are active, the second order operator splitting scheme known as Strang splitting is used. In the splitting scheme, propagation is solved using the aforementioned implicit method and the nonlinear source terms are treated explicitly using second order Runge-Kutta. Several test cases which are part of the Office for Naval Research Test Bed (ONR Test Bed) are demonstrated both with and without 3rd generation source terms and results are compared to analytic solutions, observations, and SWAN output

A GaN-Based Four-Switch Buck-Boost Converter Using Ripple Correlation Control for Maximum Power Point Tracking in Dynamic Deep Space Environments

As the demand for high-performance power conversion in spacecraft continues to grow and spacecraft mass and volume budgets become increasingly tight, it is essential to design DC-DC converters with higher efficiency and power density. Although photovoltaic (PV) efficiency has increased over time, solar irradiance and temperatures can fluctuate dramatically in deep space. This causes significant variations in the maximum power point (MPP) of the PV array, which can decrease the overall system efficiency unless accounted for. Thus, it is imperative to track the MPP of the PV panels to maintain optimal efficiency. This paper presents the experimental development of a four-switch, GaN-based buck-boost converter with an implementation of the Ripple Correlation Control (RCC) MPPT algorithm for dynamic deep space environments. Due to the use of GaN HEMTs, the experimental system achieves better efficiency and power density compared to the previous state of the art implementations. A simulation of the prototype buck-boost converter was implemented in SaberRD (Synopsis), and a digital design of the RCC-based MPPT controller utilizing the StateAMS tool is presented. The simulation results show that this controller swiftly and precisely converged to the MPP of the source PV panels in a dynamic solar irradiance condition

Cathode & Electromagnet Qualification Status and Power Processing Unit Development Update for the Ascendant Sub-kW Transcelestial Electric Propulsion System

A review of the component-level flight qualification efforts and power processing unit development status of the Ascendant Sub-kW Transcelestial Electric Propulsion System (ASTRAEUS) program is presented. Component-level qualification efforts were undertaken for the system’s ultra-compact heaterless LaB6 hollow cathode and electromagnets, both of which employ designs bespoke to ASTRAEUS, as they represent the highest failure risks for the thruster. Through parallel long-duration wear and ignition tests, the ASTRAEUS cathode demonstrated invariant discharge performance over more than 5000 h of operation at its maximum operating current of 4 A and demonstrated more than 25,000 ignition cycles. The ASTRAEUS electromagnets completed their environmental qualification through a demonstration of more than 1200 deep thermal cycles with no indication of coil degradation (the test articles previously completed qualification-level vibration and shock testing). ASTRAEUS’s prototype power processing unit has demonstrated more than 92% total power conversion efficiency and class-leading power density & specific power density of 4.5 W/cm3 & 1670 W/kg, respectively. The various power converters found in the ASTRAEUS power processing unit are reviewed with a focus on the methods by which such high performance was achieved

Demonstrating high-precision photometry with a CubeSat: ASTERIA observations of 55 Cancri e

ASTERIA (Arcsecond Space Telescope Enabling Research In Astrophysics) is a 6U CubeSat space telescope (10 cm x 20 cm x 30 cm, 10 kg). ASTERIA's primary mission objective was demonstrating two key technologies for reducing systematic noise in photometric observations: high-precision pointing control and high-stabilty thermal control. ASTERIA demonstrated 0.5 arcsecond RMS pointing stability and $\pm$10 milliKelvin thermal control of its camera payload during its primary mission, a significant improvement in pointing and thermal performance compared to other spacecraft in ASTERIA's size and mass class. ASTERIA launched in August 2017 and deployed from the International Space Station (ISS) November 2017. During the prime mission (November 2017 -- February 2018) and the first extended mission that followed (March 2018 - May 2018), ASTERIA conducted opportunistic science observations which included collection of photometric data on 55 Cancri, a nearby exoplanetary system with a super-Earth transiting planet. The 55 Cancri data were reduced using a custom pipeline to correct CMOS detector column-dependent gain variations. A Markov Chain Monte Carlo (MCMC) approach was used to simultaneously detrend the photometry using a simple baseline model and fit a transit model. ASTERIA made a marginal detection of the known transiting exoplanet 55 Cancri e ($\sim2$~\Rearth), measuring a transit depth of $374\pm170$ ppm. This is the first detection of an exoplanet transit by a CubeSat. The successful detection of super-Earth 55 Cancri e demonstrates that small, inexpensive spacecraft can deliver high-precision photometric measurements.Comment: 23 pages, 9 figures. Accepted in A

GaN-Based, Ultra-Compact Power Conversion System for the PUFFER Autonomous Mobility Platform

In the pursuit for the development of small rovers for planetary science missions, there is a distinct need for the development of an advanced, autonomously controlled, power subsystem. Existing bus management systems used in large spacecraft missions are not suitable for small spacecraft missions, as they are massive, relatively inefficient, and expensive. For extremely compact rover mission concept, newly developed high-density, high-efficiency, lightweight, and low-cost electronics are required. This paper presents a radiation-hardened power subsystem for the Pop-Up Flat-Folding Explorer Robot (PUFFER) mission concept, utilizing GaN-based converters for solar array conversion, battery management, and point of load applications to provide an extremely compact power subsystem

HD 219134 Revisited: Planet d Transit Upper Limit and Planet f Transit Nondetection with ASTERIA and TESS

HD 219134 is a K3V dwarf star with six reported radial-velocity discovered planets. The two innermost planets b and c show transits, raising the possibility of this system to be the nearest (6.53 pc), brightest (V = 5.57) example of a star with a compact multiple transiting planet system. Ground-based searches for transits of planets beyond b and c are not feasible because of the infrequent transits, long transit duration (~5 hr), shallow transit depths (<1%), and large transit time uncertainty (~half a day). We use the space-based telescopes the Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA) and the Transiting Exoplanet Survey Satellite (TESS) to search for transits of planets f (P = 22.717 days and M sin i = 7.3 ± 0.04M_⊕) and d (P = 46.859 days and M sin i = 16.7 ± 0.64M_⊕). ASTERIA was a technology demonstration CubeSat with an opportunity for science in an extended program. ASTERIA observations of HD 219134 were designed to cover the 3σ transit windows for planets f and d via repeated visits over many months. While TESS has much higher sensitivity and more continuous time coverage than ASTERIA, only the HD 219134 f transit window fell within the TESS survey's observations. Our TESS photometric results definitively rule out planetary transits for HD 219134 f. We do not detect the Neptune-mass HD 219134 d transits and our ASTERIA data are sensitive to planets as small as 3.6 R_⊕. We provide TESS updated transit times and periods for HD 219134 b and c, which are designated TOI 1469.01 and 1469.02 respectively

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Learning styles of teachers and students in a second language classrooms

honors thesisCollege of HumanitiesLinguisticsMary Ann ChristisonThe general research questions for this research study are concerned with learning styles and whether differences in student and teacher learning styles negatively impact students' perceived grades in second and foreign language classrooms. Participants were asked to take a 30-minute online questionnaire on Qualtrics to determine their perceptual learning styles, group orientation, extraversion, and tolerance for ambiguity. They come from 11 different ESL or foreign language classes, two English language classes and nine language classes offered at the University of Utah. Participants were split up into two groups, students and teachers. A t-test determined that there was no statistical difference between students' and teachers' learning styles in any subset measured. Thur, the negative perception that students have of their grade cannot be attributed to differences in learning styles alone. For students who participated on study aborad experince or an LDS mission, the responses were overwhelmingly positive, suggesting that immersion in the foreign language may be important in developing a positive orientation for language learning and may also prepare students to adapt to change