Dr. Dobb's Journal - October 2007 - (Page 42)

State of the Art by Josh Reed Software and the Core Description Process Eclipse and Java come in from the cold Core description is the process of documenting the cylindrical rock samples, called “cores,” that Josh is IT manager for the Antarctic Geological Drilling (ANDRILL) project. He can be contacted at jareed@andrill.org. result from scientific drilling. As the cores come out of the ground, they are examined and described by a team of scientists (sedimentologists) who specialize in identifying and interpreting the “stories” in the rock. The end product of this process is a series of diagrams that graphically represent the core description. These diagrams are crucial as they are the primary record of what was recovered during drilling and provide the scaffolding upon which all further scientific analysis is built. Traditionally, the core description diagrams are created first by sketching them in a field notebook, then having some poor soul—usually a graduate student— draft them up in a graphics application such as CorelDRAW or Adobe Illustrator. This creates nice, publication-quality diagrams, but sufferes from two major faults: • There is a large amount of duplicated effort because each diagram is drawn twice—once by hand, then again in digital form. • The final product is a collection of static images that cannot be easily manipulated, analyzed, or searched. Answering questions such as “what percentage of the sediment was sand?” requires visually reviewing each diagram and manually recording the features of interest. through its graphical representation, would let the scientists search for features of interest and perform further analyses more easily. Data Capture I considered three approaches to capturing the data represented in the core description diagrams: • Eliminate the diagramming altogether and have the scientists enter the data directly into spreadsheets. • Post-process the diagram images and extract the data using image analysis. • Provide an interactive drawing environment to capture the data as the diagram is drawn. The scientists rejected the first approach because it was too different from the drawing process they were familiar with, and it eliminated the diagrams— the de facto standard in conveying the core description. The second approach was promising because it did not require changing the existing process, and it held the potential to work with existing diagrams and those from future expeditions. Ultimately, I rejected this approach because of its inherent inaccuracy. There was too much variability, in both structure and style, between the few example diagrams I was provided to expect any reasonable success rate with imageanalysis techniques. I settled on providing an interactive drawing environment and capturing the core description data as the diagram is drawn. This required the This was the case with ANDRILL (www.andrill .org), a drilling project in the Antarctic on which I am the IT manager. After mulling over the problem of improving the current core description process, I came to the conclusion that the data encoded in the diagram was the key. The sedimentologists were drawing diagrams that visually represented some data (depth, grain size, rock type, and the like) without ever capturing that data itself. It’s akin to drawing a bar chart without keeping the data being charted. Is the data lost? Not really; it’s just not in a format that can be used to calculate a mean or standard deviation. Being able to access this core description data directly, instead of 42 Dr. Dobb’s Journal l www.ddj.com l October 2007 http://www.andrill.org http://www.andrill.org http://www.ddj.com

Table of Contents Feed for the Digital Edition of Dr. Dobb's Journal - October 2007

Cover Contents Hmmmm Alia Vox Developer Diaries Developer’s Notebook AI: It’s OK Again! Conversations Visual Cryptography and Bit-Plane Complexity Segmentation Inside the Windows Vista Disk Encryption Algorithm Memory-Aware Components Software and the Core Description Process Logging In C++ Effective Concurrency The Agile Edge Swaine’s Flames

Dr. Dobb's Journal - October 2007

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