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Articles 144181 - 144210 of 302480

Full-Text Articles in Physical Sciences and Mathematics

Examining Social Network Site Usage By Older Adults: A Phenomenological Approach, Betsy Baugess Mar 2015

Examining Social Network Site Usage By Older Adults: A Phenomenological Approach, Betsy Baugess

CCE Theses and Dissertations

The Internet has infiltrated our daily lives in many ways. Social networking on the Internet is a great example of how the Internet has expanded interpersonal communication. Many individuals have made social networking sites, like FaceBook and Twitter, an essential part of their lives and use these platforms to communicate daily. Until recently, young people have been the primary participants in this fast-growing phenomenon, and older adults' participation in the Internet, specifically social networking sites, has lagged far behind. However, in recent years, there has been a noteworthy increase in the number of older adult participants. The increase in older …


Correlations In Intensity Fluctuations From A Quasi-Thermal Light Source: An Application Of Hanbury Brown & Twiss, Christopher Watanabe Mar 2015

Correlations In Intensity Fluctuations From A Quasi-Thermal Light Source: An Application Of Hanbury Brown & Twiss, Christopher Watanabe

Physics

In this experiment, the observation by Hanbury Brown and Twiss that light intensity fluctuations from an extended broadband source are spatially correlated is demonstrated with a quasi-thermal light source. Laser light is used to illuminate a ground glass screen and generate a diffraction pattern, also known as a speckle pattern. The speckle pattern is recorded using an electronic camera and analyzed. Calculated auto-correlations of the intensity fluctuations agree with theoretical results originating from speckle analysis.


Simulation Of Light Scattering From Brownian Particles, Raymond Mullen Mar 2015

Simulation Of Light Scattering From Brownian Particles, Raymond Mullen

Physics

This project is a computational exploration of the light scattering from Brownian particles. We simulate laser light scattering to produce fluctuating light intensity at a detector located in the far-field. By analyzing the statistical properties of this intensity fluctuation, and knowing physical parameters of the system, we can deduce the size of the scattering particles. The computer simulation is in excellent agreement with theory.


Fission Fragment Tracking And Identification In The Neutron-Induced Fission Fragment Tracking Experiment’S Time Projection Chamber, Eric Song Mar 2015

Fission Fragment Tracking And Identification In The Neutron-Induced Fission Fragment Tracking Experiment’S Time Projection Chamber, Eric Song

Physics

The Neutron-Induced Fission Fragment Tracking Experiment (NIFFTE) built a novel Time Projection Chamber (TPC), the FissionTPC, for measuring neutron-induced fission cross-sections to unprecedented precision. We investigated data from a 2014 run (400010151) at the Los Alamos Neutron Science Center (LANSCE) with a double-sided U235/Pu239 target. Our particle identification studies will aid in the development of improved tracking algorithms.


An Extremum Principle For Charged Black Holes, Shaker Von Price Funkhouser Mar 2015

An Extremum Principle For Charged Black Holes, Shaker Von Price Funkhouser

Physics

There is a well known static condition that characterizes how two or more charged black holes stay in place: this condition is |qi |=mi , where a black hole (labeled by i) has electric charge qi and mass mi . For nearly half a century, this static condition has eluded a simple physical interpretation, without appealing to forces. I provide the first proof that the static condition, |qi |=mi , corresponds to an extremum of the black holes’ total energy. My approach uses geometry and calculus in the context of general relativity. For the non-specialist, this work draws upon one’s …


Preliminary Soil And Groundwater Assessment Of The Mantinea Development Area, East Kimberley, Western Australia, Gregory Paul Raper, Richard J. George Dr, Noel Schoknecht Mar 2015

Preliminary Soil And Groundwater Assessment Of The Mantinea Development Area, East Kimberley, Western Australia, Gregory Paul Raper, Richard J. George Dr, Noel Schoknecht

Resource management technical reports

In 2008, the Ord Stage 2 or ‘Ord East Kimberley Expansion Project’ was initiated by the Western Australian Government. The goal of the project was to advance development in the East Kimberley and to bring to market the Weaber Plain (Goomig Farmlands) and Knox Plain. In addition to the existing Ord River Irrigation Area (ORIA) Stage 1 (14 000ha), current Goomig and proposed Knox Plain areas (14 300ha), an estimated 50 000ha of land has potential for irrigation in the region.

One of the areas proposed for future development is the Mantinea Development area. It is located on the south …


Symmetric Presentations And Related Topics, Mashael U. Alharbi Mar 2015

Symmetric Presentations And Related Topics, Mashael U. Alharbi

Electronic Theses, Projects, and Dissertations

In this thesis, we have presented our discovery of symmetric presentations of a number of non-abelian simple groups, including the Mathieu group M12. We have given several progenitors, permutation and monomial, including 2*4:(22:3), 2*5:D10, 2*8:((4X2).D4), 3*7:m L2(7), 2*6:(Z3 wr Z2), and 2*24: (2. A5) and their homomorphic images which include 4.(M12:2), the group of automorphisms of M12 and several classical groups. We have given the isomorphism type of …


A Web-Based Temperature Monitoring System For The College Of Arts And Letters, Rigoberto Solorio Mar 2015

A Web-Based Temperature Monitoring System For The College Of Arts And Letters, Rigoberto Solorio

Electronic Theses, Projects, and Dissertations

In general, server rooms have restricted access requiring that staff possess access codes, keys, etc. Normally, only administrators are provided access to protect the physical hardware and the data stored in the servers. Servers also have firewalls to restrict outsiders from accessing them via the Internet. Servers also cost a lot of money. For this reason, server rooms also need to be protected against overheating. This will prolong the lifecycle of the units and can prevent data loss from hardware failure.

The California State University San Bernardino (CSUSB), Specifically the College of Arts and Letters server room has faced power …


Code Coverage And Test Suite Effectiveness: Empirical Study With Real Bugs In Large Systems, Pavneet Singh Kochhar, Ferdian Thung, David Lo Mar 2015

Code Coverage And Test Suite Effectiveness: Empirical Study With Real Bugs In Large Systems, Pavneet Singh Kochhar, Ferdian Thung, David Lo

Research Collection School Of Computing and Information Systems

During software maintenance, testing is a crucial activity to ensure the quality of program code as it evolves over time. With the increasing size and complexity of software, adequate software testing has become increasingly important. Code coverage is often used as a yardstick to gauge the comprehensiveness of test cases and the adequacy of testing. A test suite quality is often measured by the number of bugs it can find (aka. kill). Previous studies have analysed the quality of a test suite by its ability to kill mutants, i.e., artificially seeded faults. However, mutants do not necessarily represent real bugs. …


The Use Of Cmip5 Data To Simulate Climate Change Impacts On Flow Regime Within The Lake Champlain Basin, Ibrahim Nourein Mohammed, Arne Bomblies, Beverley C. Wemple Mar 2015

The Use Of Cmip5 Data To Simulate Climate Change Impacts On Flow Regime Within The Lake Champlain Basin, Ibrahim Nourein Mohammed, Arne Bomblies, Beverley C. Wemple

College of Arts and Sciences Faculty Publications

Study region: Lake Champlain Basin, northwestern New England, USA. Study focus: Our study uses regional hydrologic analyses and modeling to examine alternative possibilities that might emerge in the Lake Champlain Basin streamflow regime for various climate scenarios. Climate data as well as spatial data were processed to calibrate the Regional Hydro-Ecological Simulation System (RHESSys) model runoff simulations. The 21st century runoff simulations were obtained by driving the RHESSys model with climate data from the Coupled Model Intercomparison Project phase 5 (CMIP5) for representative concentration pathways RCP 4.5 and 8.5. New hydrological insights for the region: Our analyses suggest that most …


Mobile Agent Based Cloud Computing, Vijaya Rauniyar Mar 2015

Mobile Agent Based Cloud Computing, Vijaya Rauniyar

Culminating Projects in Computer Science and Information Technology

Cloud Computing is becoming a revolutionizing computing paradigm. It offers various types of services and applications that are being delivered in the internet cloud. The services aim at providing reliable, fault tolerant dynamic computing environment to the user and offers computing resources as per demand. Skype, Dropbox, and Yahoo mail are some of the cloud services that have major impact in our lives. Several measures are taken to maintain the quality of its service in the cloud and to make IT infrastructure available with low cost. This paper presents various aspects of Cloud Computing, its implementation features, challenges and also …


Understanding Natural Disasters As Risks In Supply Chain Management Through Web Data Analysis, Jimmy Ong, Zhaoxia Wang, Rick Siow Mong Goh, Xiao Feng Yin, Xin Xin, Xiuju Fu Mar 2015

Understanding Natural Disasters As Risks In Supply Chain Management Through Web Data Analysis, Jimmy Ong, Zhaoxia Wang, Rick Siow Mong Goh, Xiao Feng Yin, Xin Xin, Xiuju Fu

Research Collection School Of Computing and Information Systems

With the increasing trend of global outsourcing, companies are now facing ever more complexsupply chains. When a company operates over a large geographical area, the likelihood of disruptions ispotentially increased due to such unforeseen events as natural disasters, union strikes or social unrest. Inthis paper, we consider natural disasters as a form of risks in supply chains and propose to aid itsmanagement by analyzing Web data collected in real-time. Using Twitter "tweets" as our primary source ofWeb data, a real-time data crawler is developed to collect and analyze tweets that are identified as relevant tonatural disasters. In addition, a visualization …


The Case For Smartwatch-Based Diet Monitoring, Sougata Sen, Vigneshwaran Subbaraju, Archan Misra, Rajesh Krishna Balan, Youngki Lee Mar 2015

The Case For Smartwatch-Based Diet Monitoring, Sougata Sen, Vigneshwaran Subbaraju, Archan Misra, Rajesh Krishna Balan, Youngki Lee

Research Collection School Of Computing and Information Systems

We explore the use of gesture recognition on a wrist-worn smartwatch as an enabler of an automated eating activity (and diet monitoring) system. We show, using small-scale user studies, how it is possible to use the accelerometer and gyroscope data from a smartwatch to accurately separate eating episodes from similar non-eating activities, and to additionally identify the mode of eating (i.e., using a spoon, bare hands or chopsticks). Additionally, we investigate the likelihood of automatically triggering the smartwatch's camera to capture clear images of the food being consumed, for possible offline analysis to identify what (and how much) the user …


Delay Line As A Chemical Reaction Network, Josh Moles, Peter Banda, Christof Teuscher Mar 2015

Delay Line As A Chemical Reaction Network, Josh Moles, Peter Banda, Christof Teuscher

Computer Science Faculty Publications and Presentations

Chemistry as an unconventional computing medium presently lacks a systematic approach to gather, store, and sort data over time. To build more complicated systems in chemistries, the ability to look at data in the past would be a valuable tool to perform complex calculations. In this paper we present the first implementation of a chemical delay line providing information storage in a chemistry that can reliably capture information over an extended period of time. The delay line is capable of parallel operations in a single instruction, multiple data (SIMD) fashion.

Using Michaelis-Menten kinetics, we describe the chemical delay line implementation …


Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2014 Virginia Shellfish Aquaculture Crop Reporting Survey, Karen Hudson, Thomas J. Murrary Mar 2015

Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2014 Virginia Shellfish Aquaculture Crop Reporting Survey, Karen Hudson, Thomas J. Murrary

Reports

The Virginia Shellfish Aquaculture Situation and Outlook Report has been produced annually by Virginia Institute of Marine Science extension partners affiliated with Virginia Sea Grant since 2005. The survey and report provides annual assessments with which to gauge growth and inputs in Virginia’s shellfish aquaculture industry. This report is based upon an industry survey completed during the first quarter of 2015.


Personal Visualization And Personal Visual Analytics, Dandan Huang, Melanie Tory, Bon Adriel Aseniero, Lyn Bartram, Scott Bateman, Sheelagh Carpedale, Anthony Tang, Robert Woodbury Mar 2015

Personal Visualization And Personal Visual Analytics, Dandan Huang, Melanie Tory, Bon Adriel Aseniero, Lyn Bartram, Scott Bateman, Sheelagh Carpedale, Anthony Tang, Robert Woodbury

Research Collection School Of Computing and Information Systems

Data surrounds each and every one of us in our daily lives, ranging from exercise logs, to archives of our interactions with others on social media, to online resources pertaining to our hobbies. There is enormous potential for us to use these data to understand ourselves better and make positive changes in our lives. Visualization (Vis) and visual analytics (VA) offer substantial opportunities to help individuals gain insights about themselves, their communities and their interests; however, designing tools to support data analysis in non-professional life brings a unique set of research and design challenges. We investigate the requirements and research …


Managing Technical Debt: Insights From Recent Empirical Evidence, Narayan Ramasubbu, Chris F. Kemerer, C. Jason Woodard Mar 2015

Managing Technical Debt: Insights From Recent Empirical Evidence, Narayan Ramasubbu, Chris F. Kemerer, C. Jason Woodard

Research Collection School Of Computing and Information Systems

Technical debt refers to maintenance obligations that software teams accumulate as a result of their actions. Empirical research has led researchers to suggest three dimensions along which software development teams should map their technical-debt metrics: customer satisfaction needs, reliability needs, and the probability of technology disruption.


Beyond Support And Confidence: Exploring Interestingness Measures For Rule-Based Specification Mining, Bui Tien Duy Le, David Lo Mar 2015

Beyond Support And Confidence: Exploring Interestingness Measures For Rule-Based Specification Mining, Bui Tien Duy Le, David Lo

Research Collection School Of Computing and Information Systems

Numerous rule-based specification mining approaches have been proposed in the literature. Many of these approaches analyze a set of execution traces to discover interesting usage rules, e.g., whenever lock() is invoked, eventually unlock() is invoked. These techniques often generate and enumerate a set of candidate rules and compute some interestingness scores. Rules whose interestingness scores are above a certain threshold would then be output. In past studies, two measures, namely support and confidence, which are well-known measures, are often used to compute these scores. However, aside from these two, many other interestingness measures have been proposed. It is thus unclear …


Project Sourcing For Capstone Course Experience From An Undergraduate Program, Benjamin Gan, Venky Shankararaman Mar 2015

Project Sourcing For Capstone Course Experience From An Undergraduate Program, Benjamin Gan, Venky Shankararaman

Research Collection School Of Computing and Information Systems

Capstone project courses give students experience solving a substantial problem using concepts that span several topic areas in the program of study. Having 280 students graduate every year, requires a substantial effort towards sourcing appropriate projects from the industry and academia that provide hands-on opportunity to apply IT solutions to problems. This paper presents two sourcing models for supporting the sourcing of capstone projects. For each model, the various project origination sources, the distinct attributes, the challenges and lessons learnt are discussed.


Click-Boosting Multi-Modality Graph-Based Reranking For Image Search, Xiaopeng Yang, Yongdong Zhang, Ting Yao, Chong-Wah Ngo, Tao Mei Mar 2015

Click-Boosting Multi-Modality Graph-Based Reranking For Image Search, Xiaopeng Yang, Yongdong Zhang, Ting Yao, Chong-Wah Ngo, Tao Mei

Research Collection School Of Computing and Information Systems

Image reranking is an effective way for improving the retrieval performance of keyword-based image search engines. A fundamental issue underlying the success of existing image reranking approaches is the ability in identifying potentially useful recurrent patterns from the initial search results. Ideally, these patterns can be leveraged to upgrade the ranks of visually similar images, which are also likely to be relevant. The challenge, nevertheless, originates from the fact that keyword-based queries are used to be ambiguous, resulting in difficulty in predicting the search intention. Mining useful patterns without understanding query is risky, and may lead to incorrect judgment in …


Results Of Archaeogeophysical Investigations Of The Fowler - Clark Farm Mattapan, Boston, Massachusetts, Brian N. Damiata, John M. Steinberg Mar 2015

Results Of Archaeogeophysical Investigations Of The Fowler - Clark Farm Mattapan, Boston, Massachusetts, Brian N. Damiata, John M. Steinberg

Andrew Fiske Memorial Center for Archaeological Research Publications

Ground penetrating radar (GPR) and Frequency-Domain Electromagnetic (FDEM) surveys were employed over an extensively modified 50 m x 65 m city lot containing a farmhouse initially constructed between 1786 and 1806 and a later barn. Both geophysical methods suggested that most of the lot had experienced substantial disturbance and that there was limited sub - surface preservation. Both the GPR and EM surveys indicated a scatter of metallic debris and other disturbance s in the back yard at depths up to 1 m. Most of the front yard also presents as disturbed, except for two unusual but limited buried surfaces …


Assessing Usual Care In Clinical Trials, Judith A. Erlen, Lisa K. Tamres, Nancy Reynolds, Carol E. Golin, Marc I. Rosen, Robert H. Remien, Julie W. Banderas, Neil Schneiderman, Glenn Wagner, David Bangsberg, Honghu Liu Mar 2015

Assessing Usual Care In Clinical Trials, Judith A. Erlen, Lisa K. Tamres, Nancy Reynolds, Carol E. Golin, Marc I. Rosen, Robert H. Remien, Julie W. Banderas, Neil Schneiderman, Glenn Wagner, David Bangsberg, Honghu Liu

OHSU-PSU School of Public Health Faculty Publications and Presentations

Researchers designing clinical trials often specify usual care received by participants as the control condition expecting that all participants receive usual care regardless of group assignment. The assumption is that the groups in the study are affected similarly. We describe the assessment of usual care within the 16 studies in MACH 14, a multi-site collaboration on adherence to antiretroviral therapy. Only five of the studies in MACH 14 assessed usual care. Assessment protocols varied as did the timing and frequency of assessments. All usual care assessments addressed patient education focused on HIV, HIV medications, and medication adherence. Our findings support …


High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang Mar 2015

High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang

Faculty and Staff Scholarship

One of the most challenging aspects of studying galaxies in the z  7 universe is the infrequent confirmation of their redshifts through spectroscopy, a phenomenon thought to occur from the increasing opacity of the intergalactic medium to Lyα photons at z > 6.5. The resulting redshift uncertainties inhibit the efficient search for [C II] in z ~ 7 galaxies with sub-millimeter instruments such as ALMA, given their limited scan speed for faint lines. One means by which to improve the precision of the inferred redshifts is to exploit the potential impact of strong nebular emission lines on the colors of …


Morphology Parameters : Substructure Identification In X-Ray Galaxy Clusters., Viral Parekh, Kurt Van Der Heyden, Chiara Ferrari, Garry Angus, Benne W. Holwerda Mar 2015

Morphology Parameters : Substructure Identification In X-Ray Galaxy Clusters., Viral Parekh, Kurt Van Der Heyden, Chiara Ferrari, Garry Angus, Benne W. Holwerda

Faculty and Staff Scholarship

Context. In recent years multi-wavelength observations have shown the presence of substructures related to merging events in a large proportion of galaxy clusters. Clusters can be roughly grouped into two categories – relaxed and non-relaxed – and a proper characterisation of the dynamical state of these systems is crucial for both astrophysical and cosmological studies.

Aims. In this paper we investigate the use of a number of morphological parameters (Gini, M20, concentration, asymmetry, smoothness, ellipticity, and Gini of the second-order moment, GM) introduced to automatically classify clusters as relaxed or dynamically disturbed systems.

Methods. We apply our …


Subclinical Atherosclerosis And Obesity Phenotypes Among Mexican Americans, Susan T. Laing, Beverly Smulevitz, Kristina Vatcheva, Mohammad H. Rahbar, Belinda M. Reininger, David D. Mcpherson, Joseph B. Mccormick, Susan P. Fisher-Hoch Mar 2015

Subclinical Atherosclerosis And Obesity Phenotypes Among Mexican Americans, Susan T. Laing, Beverly Smulevitz, Kristina Vatcheva, Mohammad H. Rahbar, Belinda M. Reininger, David D. Mcpherson, Joseph B. Mccormick, Susan P. Fisher-Hoch

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Background

Data on the influence of obesity on atherosclerosis in Hispanics are inconsistent, possibly related to varying cardiometabolic risk among obese individuals. We aimed to determine the association of obesity and cardiometabolic risk with subclinical atherosclerosis in Mexican‐Americans.

Methods and Results

Participants (n=503) were drawn from the Cameron County Hispanic Cohort. Metabolic health was defined as <2 of the following: blood pressure ≥130/85; triglyceride ≥150 mg/dL; high‐density lipoprotein cholesterol <40 mg/dL (men) or <50 mg/dL (women); fasting glucose ≥100 mg/dL; homeostasis model assessment of insulin resistance value >5.13; or high‐sensitivity C‐reactive protein >3 mg/L. Carotid intima media thickness (cIMT) was measured. A high proportion of participants (77.8%) were metabolically unhealthy; they were more likely to be male, older, with fewer years of education, and less likely to meet daily recommendations regarding …


Mismorphism: A Semiotic Model Of Computer Security Circumvention (Extended Version), Sean W. Smith, R Koppel, J Blythe, V Kothari Mar 2015

Mismorphism: A Semiotic Model Of Computer Security Circumvention (Extended Version), Sean W. Smith, R Koppel, J Blythe, V Kothari

Computer Science Technical Reports

In real world domains, from healthcare to power to finance, we deploy computer systems intended to streamline and improve the activities of human agents in the corresponding non-cyber worlds. However, talking to actual users (instead of just computer security experts) reveals endemic circumvention of the computer-embedded rules. Good-intentioned users, trying to get their jobs done, systematically work around security and other controls embedded in their IT systems. This paper reports on our work compiling a large corpus of such incidents and developing a model based on semiotic triads to examine security circumvention. This model suggests that mismorphisms---mappings that fail to …


Judicious Use Of Communication For Inherently Parallel Optimization, Andrew W. Mcnabb Mar 2015

Judicious Use Of Communication For Inherently Parallel Optimization, Andrew W. Mcnabb

Theses and Dissertations

Function optimization---finding the minimum or maximum of a given function---is an extremely challenging problem with applications in physics, economics, machine learning, engineering, and many other fields. While optimization is an active area of research, only a portion of this work acknowledges parallel computation, which is now widely available. Today, anyone with a modest budget can buy a cluster with hundreds of cores, pay for access to a supercomputer with thousands of processors, or at least purchase a laptop with 8 cores. Thus, an algorithm that works well in serial but cannot be parallelized is needlessly inefficient in real-life computationalenvironments.We address …


A Mathematical Model Of Amoeboid Cell Motion As A Continuous-Time Markov Process, Lynnae Despain Mar 2015

A Mathematical Model Of Amoeboid Cell Motion As A Continuous-Time Markov Process, Lynnae Despain

Theses and Dissertations

Understanding cell motion facilitates the understanding of many biological processes such as wound healing and cancer growth. Constructing mathematical models that replicate amoeboid cell motion can help us understand and make predictions about real-world cell movement. We review a force-based model of cell motion that considers a cell as a nucleus and several adhesion sites connected to the nucleus by springs. In this model, the cell moves as the adhesion sites attach to and detach from a substrate. This model is then reformulated as a random process that tracks the attachment characteristic (attached or detached) of each adhesion site, the …


Simulations Of Electron Trajectories In An Intense Laser Focus For Photon Scattering Experiments, Grayson J. Tarbox Mar 2015

Simulations Of Electron Trajectories In An Intense Laser Focus For Photon Scattering Experiments, Grayson J. Tarbox

Theses and Dissertations

An experiment currently underway at BYU is designed to test whether the size of a free electron wave packet affects the character of scattered radiation. Using a semi-classical argument wherein the wave packet is treated as a diffuse charge distribution, one would expect strong suppression of radiation in the direction perpendicular to the propagating field as the wave packet grows in size to be comparable to the wavelength of the driving field. If one disallows the interaction of the wave packet with itself, as is the case when calculating the rate of emission using QED, then regardless of size, the …


The Small Binary Asteroid (939) Isberga, B. Carry, A. Matter, P. Scheirich, P. Pravec Mar 2015

The Small Binary Asteroid (939) Isberga, B. Carry, A. Matter, P. Scheirich, P. Pravec

University Faculty Publications and Creative Works

In understanding the composition and internal structure of asteroids, their density is perhaps the most diagnostic quantity. We aim here at characterizing the surface composition, mutual orbit, size, mass, and density of the small main-belt binary asteroid (939) Isberga. For that, we conduct a suite of multi-technique observations, including optical lightcurves over many epochs, near-infrared spectroscopy, and interferometry in the thermal infrared. We develop a simple geometric model of binary systems to analyze the interferometric data in combination with the results of the lightcurve modeling. From spectroscopy, we classify Ibserga as a Sq-type asteroid, consistent with the albedo of 0.14-0.06+0.09 …