A5013179348- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Data Visualization and Analytics
- Digital Games and Media
- Impact of Technology on Adolescents
- Scientific Computing and Data Management
- Human-Automation Interaction and Safety
- Aerospace and Aviation Technology
- Neutrino Physics Research
- Innovative Teaching and Learning Methods
- Digital Communication and Language
- Astrophysical Phenomena and Observations
- Air Traffic Management and Optimization
- Ethics and Social Impacts of AI
- Pulsars and Gravitational Waves Research
- Astronomical Observations and Instrumentation
- Complex Network Analysis Techniques
- Advanced Text Analysis Techniques
- Educational Games and Gamification
- Reflective Practices in Education
- Team Dynamics and Performance
- Astro and Planetary Science
- Mentoring and Academic Development
University of Washington
2016-2025
Sandia National Laboratories
2020-2024
Dakota State University
2024
North Dakota State University
2024
Wyoming Department of Education
2024
University of Wyoming
2024
Bilkent University
2024
Lawrence Berkeley National Laboratory
2012-2023
Seattle University
2013-2023
Los Alamos National Laboratory
2022
In this and two companion papers, we report on an extended empirical study of the simulated annealing approach to combinatorial optimization proposed by S. Kirkpatrick et al. That investigated how best adapt particular problems compared its performance that more traditional algorithms. This paper (Part I) discusses our parameterized generic implementation it, describes adapted algorithm graph partitioning problem, reports well it standard algorithms like Kernighan-Lin algorithm. (For sparse...
This is the second in a series of three papers that empirically examine competitiveness simulated annealing certain well-studied domains combinatorial optimization. Simulated randomized technique proposed by S. Kirkpatrick, C. D. Gelatt and M. P. Vecchi for improving local optimization algorithms. Here we report on experiments at adapting to graph coloring number partitioning, two problems which had not previously been thought suitable. For coloring, schemes, all can dominate traditional...
We present photometric and spectroscopic observations of SN 2007if, an overluminous (MV = −20.4), red (B − V 0.16 at B-band maximum), slow-rising (trise 24 days) type Ia supernova (SN Ia) in a very faint (Mg −14.10) host galaxy. A spectrum 5 days past maximum light is direct match to the super-Chandrasekhar-mass candidate 2003fg, showing Si ii C ∼9000 km s−1. high signal-to-noise co-addition spectral time series reveals no Na i D absorption, suggesting negligible reddening galaxy, late-time...
Previously we used the Nearby Supernova Factory sample to show that Type Ia supernovae (SNe Ia) having locally star-forming environments are dimmer than SNe passive environments. Here use Constitution together with host galaxy data from GALEX independently confirm result. The effect is seen using both SALT2 and MLCS2k2 lightcurve fitting standardization methods, brightness differences of 0.094 ± 0.037 mag for 0.155 0.041 RV = 2.5. When combined our previous measurement 0.025 SALT2. If ratio...
Pulsed power accelerators compress electrical energy in space and time to provide versatile experimental platforms for high density inertial confinement fusion science. The 80-TW “Z” pulsed facility at Sandia National Laboratories is the largest device world today. Z discharges up 22 MJ of stored its capacitor banks into a current pulse that rises 100 ns peaks as 30 MA low-inductance cylindrical targets. Considerable progress has been made over past 15 years use precision scientific tool....
As part of an on-going effort to identify, understand and correct for astrophysics biases in the standardization Type Ia supernovae (SNIa) cosmology, we have statistically classified a large sample nearby SNeIa into those located predominantly younger or older environments. This classification is based on specific star formation rate measured within projected distance 1kpc from each SN location (LsSFR). important refinement compared using local directly as it provides normalization relative...
We examine the relationship between Type Ia supernova (SN Ia) Hubble residuals and properties of their host galaxies using a sample 115 SNe from Nearby Supernova Factory. use galaxy stellar masses specific star formation rates fitted photometry for all hosts, as well gas-phase metallicities subset 69 star-forming (non-active galactic nucleus) to show that SN correlate with each these properties. With data we find new evidence correlation intrinsic color metallicity. When combine our those...
We present VizDeck, a web-based tool for exploratory visual analytics of unorganized relational data. Motivated by collaborations with domain scientists who search complex patterns in hundreds data sources simultaneously, VizDeck automatically recommends appropriate visualizations based on the statistical properties and adopts card game metaphor to help organize recommended into interactive dashboard applications seconds zero programming. The demonstration allows users derive, share,...
We present a sample of normal Type Ia supernovae (SNe Ia) from the Nearby Supernova Factory data set with spectrophotometry at sufficiently late phases to estimate ejected mass using bolometric light curve. measure 56Ni masses peak luminosity, then compare luminosity in 56Co-decay tail expected rate radioactive energy release ejecta given mass. infer Bayesian context semi-analytic model ejecta, incorporating constraints contemporary numerical models as priors on density structure and...
Machine learning (ML) has become increasingly influential to human society, yet the primary advancements and applications of ML are driven by research in only a few computational disciplines. Even that affect or analyze behaviors social structures often developed with limited input from experts outside fields. Social scientists—experts trained examine explain complexity behavior interactions world—have considerable expertise contribute development for human-generated data, their analytic...
(Abridged) We study the host galaxy regions in close proximity to Type Ia supernovae (SNe Ia) analyze relations between properties of SN events and environments most similar where their progenitors formed. focus on local H\alpha\ emission as an indicator young environments. The Nearby Supernova Factory has obtained flux-calibrated spectral timeseries for SNe using integral field spectroscopy, allowing simultaneous measurement its immediate vicinity. For 89 we measure tracing ongoing star...
A randomized strategy for maintaining balance in dynamically changing search trees that has optimal expected behavior is presented. In particular, the case an update takes logarithmic time and requires fewer than two rotations. Moreover, remains logarithmic, even if cost of a rotation taken to be proportional size rotated subtree. The approach generalizes naturally weighted trees, where bounds accesses updates again match worst best deterministic methods. balancing algorithms are exceedingly...
We employ 76 type Ia supernovae with optical spectrophotometry within 2.5 days of B-band maximum light obtained by the Nearby Supernova Factory to derive impact Si and Ca features on intrinsic luminosity determine a dust reddening law. use equivalent width II {\lambda}4131 in place curve stretch account for first-order variability. The resultant empirical spectral law exhibits strong associated {\lambda}6355. After applying correction based H&K we find consistent Cardelli extinction Using...
We present a new atmospheric extinction curve for Mauna Kea spanning 3200--9700 \AA. It is the most comprehensive to date, being based on some 4285 standard star spectra obtained 478 nights spread over period of 7 years by Nearby SuperNova Factory using Integral Field Spectrograph. This mean and its dispersion can be used as an aid in calibrating spectroscopic or imaging data from Kea, estimating calibration uncertainty associated with use curve. Our method decomposing into physical...
We present a new method to standardize type Ia supernova (SN Ia) luminosities 0.13 mag using flux ratios from single flux-calibrated spectrum per SN. Using Nearby Supernova Factory spectrophotomery of 58 SNe Ia, we performed an unbiased search for that correlate with SN luminosity. After developing the and selecting best training sample, verified results on separate validation sample data literature. identified multiple whose correlations luminosity are stronger than those light curve shape...
There has been much recent interest in the development of tools to foster remote collaboration and shared creative work. An open question is: what are guidelines for this process? What key socio-technical preconditions required a geographically distributed group collaborate effectively on work, they different from conditions decade or two ago? In an attempt answer these questions, we conducted empirical studies seemingly very online communities, both requiring effective work: international...
There has been increased interest in reliable, non-intrusive methods of biometric identification due to the growing emphasis on security and increasing prevalence identity theft. This paper presents a new approach that involves an estimation unique oculomotor plant (OP) or eye globe muscle parameters from movement trace. These model individual properties human eye, including neuronal control signal, series elasticity, length tension, force velocity, active tension. can be estimated for each...
We present optical photometry and spectroscopy of five Type Ia supernovae discovered by the Nearby Supernova Factory selected to be spectroscopic analogs candidate super-Chandrasekhar-mass events SN 2003fg 2007if. Their spectra are characterized hot, highly ionized photospheres near maximum light, for which 1991T supplies best phase coverage among available close spectral templates. Like 2007if, these overluminous (−19.5 < MV −20) velocity Si ii λ6355 absorption minimum is consistent with...
Context. Our Local Group of galaxies appears to be moving relative the cosmic microwave background with source peculiar motion still uncertain. While in past this has been studied mostly using as distance indicators, weight type Ia supernovae (SNe Ia) increased recently continuously improving statistics available low-redshift supernovae. Aims. We measured bulk flow nearby universe ($0.015 < z 0.1$) 117 SNe observed by Nearby Supernova Factory, well Union2 compilation SN data already...
We present convincing evidence of unburned carbon at photospheric velocities in new observations 5 Type Ia supernovae (SNe Ia) obtained by the Nearby Supernova Factory. These SNe are identified examining 346 spectra from 124 before +2.5 d relative to maximum. Detections based on presence relatively strong C II 6580 absorption "notches" multiple each SN, aided automated fitting with SYNAPPS code. Four question otherwise spectroscopically unremarkable, ions and ejection typical Ia, but fifth...
A novel biometrics approach that performs authentication via the internal non-visible anatomical structure of an individual human eye is proposed and evaluated. To provide authentication, method estimates characteristics oculomotor plant (comprising globe, its muscles brain's control signals). The estimation (OPC) achieved by analyzing recorded movement trajectories a 2D linear homeomorphic mathematical representation plant. derived OPC allow various statistical methods information fusion...
Geographically distributed collaborative teams often rely on synchronous text-based online communication for accomplishing tasks and maintaining social contact. This technology leaves a trace that can help researchers understand affect expression dynamics in groups. Although manual labeling of chat logs has shed light complex group phenomena, scaling this process to larger data sets through automation is difficult. We present pipeline natural language processing machine learning techniques...
Young people worldwide are participating in ever-increasing numbers online fan communities. Far from mere shallow repositories of pop culture, these sites accumulating significant evidence that sophisticated informal learning is taking place novel and unexpected ways. In order to understand analyze more detail how might be occurring, we conducted an in-depth nine-month ethnographic investigation fanfiction communities, including participant observation author interviews. Our observations led...