Monday, April 20, 2015

2015-04-20: Virginia Space Grant Consortium Student Research Conference Report

Mat Kelly and various other graduate students in the state of Virginia present their graduate research at the Virginia Space Grant Consortium.                           

On Friday, April 17, 2015 I attended the Virginia Space Grant Consortium (VSGC) Student Research Conference at NASA Langley Research Center (LaRC) in Hampton, Virginia. This conference is slightly beyond the scope of what we at ODU WS-DL (@webscidl) usually investigate, as the research requirement was that it was relevant to NASA's objectives as a space agency.

My previous work with LaRC's satellite imagery allowed me to approach the imagery files with the perspective a computational scientist. More on my presentation, "Facilitation of the A Posteriori Replication of Web Published Satellite Imagery" below.

The conference started off with registration and a provided continental breakfast. Mary Sandy, the VSGC Director and Chris Carter, the VSGC Deputy Director began by describing the history of the Virginia Space Grant Consortium program including the amount contributed since its inception and the number of recipients that have benefitted from being funded.

The conference was organized in a model consisting of concurrent sessions of two to three themed presentations by undergraduate and graduate students at various Virginia universities.

First Concurrent Sessions

I attended the "Aerospace" session in the first morning session. In this session Maria Rye (Virginia Tech) started with her explorative research in suppressing distortions in tensegrity systems, a flexible structure held together by interconnected bars and tendons.

Marie Ivanco (Old Dominion University) followed Maria with her research in applying Analytic Hierarchy Processes (AHPs) for analytical sensitivity analysis and local inconsistency checks for engineering applications.

Peter Marquis (Virginia Tech) spoke third in the session with his research on characterizing the design variables to trim the LAICE CubeSat to obtain a statically stable flight configuration.

Second Concurrent Sessions

The second sessions seamlessly continued with Stephen Noel (Virginia Tech) presenting a similar work relating to LAICE. His work consisted of the development of software to read, parse, and interpret calibration data for the system.

Cameron Orr (Virginia Tech) presented the final work in the second Aerospace session with the exploration of the development of adapted capacitance manometers for thermospheric applications. Introducing this additional component as well as some detection circuitry allowed more accurate measurement of pressure changes.

Third Concurrent Sessions

After a short break where posters from graduate students around Virginia were presented, I opted to move to another room to view the Applied Science presentations.

Atticus Stovall (University of Virginia) described his system for modeling forest carbon relating height-to-biomass relationships as well as voxel based volume modeling as a means of evaluating the amount of carbon stored.

Matthew Giarra (Virginia Tech) wrapped up the short session with a visual investigation of the flow of hemolymph (blood) in insects' bodies as a potential model for non-directional fluid pumping.

Fourth Concurrent Sessions

The third session immediately segued into the fourth session of the day, where I changed rooms to attend the Astrophysics presentations.

Charles Fancher (William & Mary) presented work on a theoretical prototype for an ultracold atom-based magnetometer for accurate timekeeping in space.


John Blalock (Hampton University) presented next in the Astrophysics session with his work on using various techniques to measure wind speeds on Saturn from the results returned by the Cassini orbiter's Imaging Science Subsystem.


Kimberly Sokal (University of Virginia) wrapped up the fourth session with her enthusiastic presentation on emerging super star clusters with Wolf-Rayet stars. Her group's discovery of the star cluster S26 in NGC 4449 is undergoing an evolutionary transition that is not well understood. The ongoing work may provide feedback as to the tipping point of the emerging process that affects the super star cluster's ability to remain bound.

The conference then broke for an invitation-only lunch with a keynote address by Dr. David Bowles, Acting Directory of NASA Langley Research Center.

Fifth Concurrent Sessions

For the final session of the day, I attended and presented at the Astrophysics session. Emily Mitchell (University of Virginia) presented first with her study on the irradiation effects of H2-laden porous water ice films in the interstellar medium (ISM). She exposed ice to hydrogen gas at different pressures after deposition and during radiation. She reports that H2 concentration increases with decreasing ion flux, suggesting that as much as 7 percent solid H2 is trapped in interstellar ice by radiation impacts

Following Emily, Mat Kelly (your author) of Old Dominion University presented my work on the Facilitation of the A Posteriori Replication of Web Published Satellite Imagery. By creating software to mine the metadata and a system that allows peer-to-peer sharing of the public domain satellite imagery currently solely located on the NASA Langley servers, I was able to mitigate the reliance on a single source of the data. The system I created utilizes concepts from ResourceSync, BitTorrent and WebRTC.

Wrap Up

The Virginia Space Grant Consortium Student Research Conference was extremely interesting despite being somewhat different in topic compared to our usual conferences. I am very glad that I got the opportunity to do the research for the fellowship and hope to progress the work for further applications beyond satellite imagery.

Mat (@machawk1)

Sunday, April 5, 2015

2015-04-05: From Student To Researcher...

In 2010, I decided to again study at the Old Dominion University Computer Science Department for better employment opportunities. After taking some classes, I realized that I did not merely want to take classes and earn a Master's Degree, but also wanted to contribute knowledge, like those who wrote the many research papers I had read during my courses.

My Master's Thesis is titled "Avoiding Spoilers On MediaWiki Fan Sites Using Memento".   I came to the topic via a strange route.

During Dr. Nelson's Introduction to Digital Libraries course, we built a digital library based on a single fictional universe.  I chose the television show Lost, and specifically archived Lostpedia, a site that my wife and I used while watching and discussing the show.  We realized that fans were updating Lostpedia while episodes aired.  This highlighted the idea that wiki revisions created prior to the episode obviously did not contain information about that episode, and emphasized that episodes led to wiki revisions.

A few years later, a discussion at work occurred while watching Game of Thrones.  I realized that some of us had seen the episode of the night before while others had not.  We wanted to use the Game of Thrones Wiki to continue our conversation, but realized that those who had not seen the episode easily encountered spoilers.  By this point, I was quite familiar with Memento, had used Memento for Chrome, and was working on the Memento MediaWiki Extension.  The idea of using Memento to avoid spoilers was born.

The figure above exhibits the Naïve Spoiler Concept.  The concept is that wiki revisions in the past of a given episode should not contain spoilers, because information has not yet been revealed by the episode, hence fans could not write about it.  Inversely, wiki revisions in the future of a given episode will likely contain spoilers, seeing as episodes cause fans to write wiki revisions.

It turned out that there was more to avoiding spoilers in fan wiki sites than merely using Memento and the Naïve Spoiler Concept.  Most TimeGates use a heuristic that is not reliable for avoiding spoilers, so I proposed a new one and demonstrated why the existing heuristic was insufficient by calculating the probability of encountering a spoiler using the current heuristic.  I also used the Memento MediaWiki Extension to demonstrate this new heuristic in action.  In this way I was able to develop a Computer Science Master's Thesis on the topic.

Mindist (minimum distance) is the heuristic used by most TimeGates. This works well for an sparse archive, because often the closest memento to the datetime you have requested is best.  Wikis have access to every revision, allowing us to use a new heuristic minpast (minimum distance in the past, minimum distance without going over the given date).  Using records from fan wikis, I showed that, if one is trying to avoid spoilers, there can be as much as a 66% chance of encountering a spoiler if we use the Wayback Machine or a Memento TimeGate using mindist.  I also analyzed Wayback Machine logs for wikia.com requests and found that 19% of those requests ended up in the future.  From these studies, it was clear that using minpast directly on wikis was the best way to avoid spoilers.

While I was examining fan wikis for spoilers, I also had the opportunity to compare wiki revisions with mementos recorded by the Internet Archive.  Using this information I was actually able to reveal how the Internet Archive's sparsity is changing over time.  Because wikis keep track of every revision, so we can see missed updates by the Internet Archive.

In the figure above, we see a timeline for each wiki page I conducted in the study.  The X-axis shows time and the Y-axis consists of an identifier for each wiki page.  Darker colors indicate more missed updates by the Internet Archive.  We see that the colors are getting lighter, meaning that the Internet Archive has becoming more aggressive in recording pages.

Below are the slides for the presentation, available on my SlideShare account, followed by the video of my defense posted to YouTube.  The full document of my Master's Thesis is available here.







Thanks to Dr. Irwin Levinstein and Dr. Michele Weigle for serving on my committee.  Their support has been invaluable during this process. Were it not for Dr. Levinstein, I would not have been able to become a graduate student.  Were it not Dr. Weigle's wonderful Networking class, I would not have been able to draw some of the conclusions necessary to complete this thesis.

Much of the thanks goes to my advisor, Dr. Michael L. Nelson, who spent hours discussing these concepts with me, helping correct my assumptions and assessments when I erred, while praising the experience when I came up with something original and new.  His patience and devotion not only to the area of study, but also the art of mentoring, led me down the path of success.

In the process of creating this thesis, I also created a technical report which can be referenced using the BibTeX code below.



So, what is next?  Do I use wikis to study the problem of missed updates in more detail? Do I study the use of the naïve spoiler concept in another setting?  Or do I do something completely different?

I realize that I have merely begun my journey from student to researcher, but know even more now that I will enjoy the path I have chosen.

--Shawn M. Jones, Researcher