I. Introduction.- 1. Set Systems and Languages.- 2. Graphs, Partially Ordered Sets and Lattices.- II. Abstract Linear Dependence - Matroids.- 1. Matroid Axiomatizations.- 2. Matroids and Optimization.- 3. Operations on Matroids.- 4. Submodular Functions and Polymatroids.- III. Abstract Convexity - Antimatroids.- 1. Convex Geometries and Shelling Processes.- 2. Examples of Antimatroids.- 3. Circuits and Paths.- 4. Helly's Theorem and Relatives.- 5. Ramsey-type Results.- 6. Representations of Antimatroids.- IV. General Exchange Structures - Greedoids.- 1. Basic Facts.- 2. Examples of Greedoids.- V. Structural Properties.- 1. Rank Function.- 2. Closure Operators.- 3. Rank and Closure Feasibility.- 4. Minors and Extensions.- 5. Interval Greedoids.- VI. Further Structural Properties.- 1. Lattices Associated with Greedoids.- 2. Connectivity in Greedoids.- VII. Local Poset Greedoids.- 1. Polymatroid Greedoids.- 2. Local Properties of Local Poset Greedoids.- 3. Excluded Minors for Local Posets.- 4. Paths in Local Poset Greedoids.- 5. Excluded Minors for Undirected Branchings Greedoids.- VIII. Greedoids on Partially Ordered Sets.- 1. Supermatroids.- 2. Ordered Geometries.- 3. Characterization of Ordered Geometries.- 4. Minimal and Maximal Ordered Geometries.- IX. Intersection, Slimming and Trimming.- 1. Intersections of Greedoids and Antimatroids.- 2. The Meet of a Matroid and an Antimatroid.- 3. Balanced Interval Greedoids.- 4. Exchange Systems and Gauss Greedoids.- X. Transposition Greedoids.- 1. The Transposition Property.- 2. Applications of the Transposition Property.- 3. Simplicial Elimination.- XI. Optimization in Greedoids.- 1. General Objective Functions.- 2. Linear Functions.- 3. Polyhedral Descriptions.- 4. Transversals and Partial Transversals.- 5. Intersection of Supermatroids.- XII. Topological Results for Greedoids.- 1. A Brief Review of Topological Prerequisites.- 2. Shellability of Greedoids and the Partial Tutte Polynomial.- 3. Homotopy Properties of Greedoids.- References.- Notation Index.- Author Index.- Inclusion Chart (inside the back cover).

This research addresses the problem of tracking digital information that is shared using peer-to-peer file transfer and VoIP protocols for the purposes of illicitly disseminating sensitive government information and for covert communication by terrorist cells or criminal organizations. A digital forensic tool is created that searches a network for peer-to-peer control messages, extracts the unique identifier of the file or phone number being used, and compares it against a list of known contraband files or phone numbers. If the identifier is on the list, the control packet is saved for later forensic analysis. The system is implemented using an FPGA-based embedded software application, and processes file transfers using the BitTorrent protocol and VoIP phone calls made using the Session Initiation Protocol (SIP). Results show that the final design processes peer-to-peer packets of interest 92% faster than a software-only configuration, and is able to successfully capture and process BitTorrent Handshake messages with a probability of at least 99.0% and SIP control packets with a probability of at least 97.6% under a network traffic load of at least 89.6 Mbps.

This thesis examines the military career of Major General Benjamin Foulois to determine how his personal qualities and professional skill enabled him rapidly to build up and lead the air arm of the American Expeditionary Forces to victory in World War I. While previous academic works have focused on Foulois' early aviation career from 1909 to 1916 and his tenure as Chief of the Air Corps from 1931 to 1935, no treatment exists that details the vital role he played in the development of the American Air Service leading up to and during World War I. Foulois' personal and moral courage allowed him to take on the weighty responsibility of designing and executing a $640 million plan to create a combat air force from scratch. After his poor performance as Chief of Air Service, this same courage enabled him to learn from his mistakes and return to the Air Service staff to complete the organizational buildup he started. His skill as a political infighter gave him the ability to advocate patiently for the air arm's interests within the halls of Congress and the War Department instead of following Billy Mitchell's example of using the blunt instrument of criminal accusations in the court of public opinion to effect change. Foulois' leadership record during the War was mixed; and he was much more effective as a logistician and troubleshooter for solving the Air Service's training, aircraft production, and contracting problems than as a combat leader on the front. While Foulois was one of the world's first writers on airpower theory, he chose to focus his later career on developing the technological and organizational innovations he felt were required in order to bring the airpower theories of others such as Mitchell, Giulio Douhet, and Hugh Trenchard to fruition. Foulois' leadership, tenacity, forward thinking, and organizational skill hold lessons for future Air Force leaders charged with a similar rapid establishment or expansion of new capabilities, such as a robust remotel