My research is primarily in the area of scalability and web performance, and is often influenced by a decade of work and involvement as a system administrator supporting large online communities. My PhD research advisor is Dr. Haining Wang.
While static web technologies have reached a level of stability with regard to optimizations in server performance, dynamic web sites offer much greater degrees of both variability and complexity, and as a result, there are many competing opportunities for optimizing their complex interactions. This includes caching at 8 different service layers, language optimizations, code optimizations, software engineering, database optimizations, distributed and parallel computing, and much more.
Adding in dynamic provisioning and virtualization (cloud computing), plus an examination of non-traditional inputs (requests from search engines, web services, and mobile devices), the interactions and trade-offs between horizontal and vertical scaling—this area of research is very exciting to me!
Haitao Xu, Daiping Liu, Aaron Koehl, Haining Wang, Angelos Stavrou.
Click Fraud Detection on the Advertiser Side. ESORICS, Sept. 2014: 419-438
Jing Jin, Jeff Offutt, Nan Zheng, Feng Mao, Aaron Koehl, and Haining Wang,
Evasive Bots Masquerading as Human Beings on the Web,
In IEEE DSN 2013, Budapest, Hungary, June 2013.
Zi Chu, Steven Gianvecchio, Aaron Koehl, Haining Wang, and Sushil Jajodia,
Blog or Block: Detecting Blog Bots through Behavioral Biometrics,
In Computer Networks (COMNET), Vol. 57, No. 3, February 2013.
Aaron Koehl and Haining Wang,
m.Site: Efficient Content Adaptation for Mobile Devices,
In ACM/IFIP/USENIX Middleware 2012, Montreal, Canada, December 2012.
Inland waterways intermodal transportation system design and feasibility analysis – Expanding the use of our nation's inland and coastal waterways system to improve freight productivity and protect our environment. Master's Capstone, prepared for Office of Intermodal Development, US Maritime Administration, and US Dept. of Transportation. University of Virginia, 2005.
Others currently under submission.
Scalability and Performance Implications of Middleware for Non-Traditional Web Clients. (Oral exam complete) [Abstract]
When I am not teaching and doing research: I love to cook and eat. I love to play music. I also enjoy travelling with my family, and playing with my 2-year old daughter. Beyond that, I like computer controlled woodworking equipment (lasers and CNC routers). I also like to work in vector graphic design for various media (large format, print media, vinyl signage, embroidery), 3D architectural modeling, and photo editing. That about sums it up!
I love to dine out; when I travel, finding a new dish to bring home to remember the trip by is among my primary goals. I also love to discover, eat, and learn to cook regional cuisine; this is one of the best ways to absorb a culture. If you click on my food link, you can see what I have been cooking up.
I have loved music for as long as I can remember, starting with the toy keyboards at age 3 (to hear my mother tell the story). My jazz trio plays throughout the area, and in addition I perform a dozen or so weddings each year. April through October is the biggest time for weddings here in Eastern Virginia. Most of my weddings are at the wonderful, historic Select Registry property Inn at Warner Hall, originally land-granted to George Washington's great-grandparents, Mildred and Augustine Warner. You can catch me sitting in with a number of other musical groups in the area as well. I have also been a church pianist for 18 years. All in all, I play about 80-90 engagements a year.
Gear: Roland KR575, Roland RD700SX, Roland DP-8 pedal, two 1000W QSC K8's, two ElectroVoice SXA100's, Boss RC505, Alesis Mixer, two Shure SM58's, and an AudioTechnica AT2020.
I have a wonderful wife, whom I married in 2007, and a wonderful 2 year old daughter. My wife says she married me for my cooking; I'm okay with this. I do all of the cooking, but it means I always get to eat what I want. :) My wife does pick up a mean take-out. We actually started dating in high school just before senior prom; in a couple years, I will have known her longer than I haven't. That's saying something! You can see some of our travels here.
Full-time Professor at Christopher Newport University
Click any link to see my syllabi as instructor of record.
Each spring, we hold a software fair to exhibit undergraduate computer science and information systems capstone projects. In the book Innumeracy (Paulos), a story is told of 5th grade students who are provided a math problem. The same math problem is given to college professors, graduate students, high schoolers, and the like, with only the 5th graders doing well on the problem. The difference is that the young students have the benefit of the context of the chapter in which they recently studied. The capstone experience is similar: a guided project without the context of a chapter. Students must identify resources and tools to solve a real problem with inherent ambiguity; this offers the students considerable self-discovery of their limits, practice in time management and estimation, and offers a means for students to put their learned skills to the test. As a requirement, it also fosters the crucial skill of independent learning, as the students must identify supporting resources and employ tools which they have yet to learn.
I have the wonderful opportunity to coordinate this event, and to mentor each project. It is very fulfilling to guide the students through the formal process of proposal, identification of resources, project management (agile), and ultimately watch as the students innovate and create in a 14 week period. Here is the program from the spring 2014 capstone exhibition and software fair. Additionally, six of the projects were featured in the undergraduate conference Paideia, held at CNU each year.
Full CV available upon request.
Software / Project Management Highlights
Active Systems Expertise
Databases (Oracle / PLSQL, MySQL, MSSQL Server; Data modeling, design, optimization, and integration)
Operating Systems (Linux, Windows, Server Administration)
Virtualization (VMWare, Xen)
Media Design (Vector and raster, print media design, Photoshop)
CNC (Trotec/Epilog Lasers, ShopBot / CAMMaster CNC Routers, GraphTEC vinyl plotters, Vectric Aspire, 3-axis machining)
Affiliations / Professional Roles
Board of Directors, CNU Alumni Association (07-10)
President, William and Mary CS Graduate Student Association (09-10)
Campaign Manager, Sheriff Election Campaign, Gloucester, VA (10-11)
Administrator, SawmillCreek.org Woodworking Community
Alumni Member, Phi Mu Alpha Music Organization
Upsilon Pi Epsilon, International Honor Society for Computing and Information Disciplines
ACM Member (Association of Computing Machinery)
Member, Oracle Development Tools (ODTUG) User's Group
Chair, Undergraduate Admissions Committee (CNU University Committee)
Chair, Information Systems and Information Science Committee (CNU)
INCOSE-HRA'13 Conference Committee, Host (CNU / INCOSE)
Plenary Panel Moderator, INCOSE-HRA'13
Member, Computer Science Curriculum Committee (CNU)
Professional Jazz Pianist (Aaron Koehl Trio)
Pianist, Severn Church
Sailing Race Crew, York River Yacht Club Racing Series
Hospital Volunteer, Riverside Regional Medical Center
Journal of Web Engineering
Journal of Computer Networks
Int'l Conference on Computer Communications
Security and Communication Networks
Int'l Conference of Dependable Systems and Networks
Stuff You Didn't Know About Me and Would Probably Never Ask
I was a drum major in high school; our band and guard had about 250 students. I danced on the field as part of our routine to the song "Angel Eyes", as part of our jazz/swing field show.
I played Prince Humperdinck in a stage adaptation of The Princess Bride. I still remember most of my lines.
I was a LTJG officer cadet in NJROTC, and attended two week-long sea cruises aboard the USS Gunston Hall (LSD, an amphibious warfare ship) and the USS Arctic (AOE-8, a fast combat support ship). AOE stands for auxiliary, oiler, and explosives; LSD stands for landing ship dock.
When not busy researching, I sail during racing season on the York River, aboard the sailing yacht Camden, a Tartan 37.
We started a 501-c-3 called the Freedom Pens Project, providing hand-crafted pens (turned on a lathe) to troops overseas. We have shipped 166,484 pens since the program's inception in 2004.
I own and have seen all 7 seasons of Star Trek: TNG. Big fan. How surprised are you that a computer scientist would watch Star Trek?
I have two dogs; a catahoula leopard dog/german shepherd mix, and a border collie mix. As expected, the border collie is a Frisbee-seeking missile. I won a bottle of Appleton Rum in a Frisbee throwing competition at a resort in Jamaica, due entirely to my practice throwing frisbees to my dog.
I own a small front-loader, just to reinforce the stereotype that people from Gloucester all own tractors. It's a Kubota BX1500 with a belly mower, shovel, and a blade.
I was born in Williamsburg, VA.