Calibration of the 13- by 13-inch adaptive wall test section for the Langley 0.3-meter transonic cryogenic tunnel

A 13 by 13 inch adaptive wall test section was installed in the 0.3 Meter Transonic Cryogenic Tunnel circuit. This new test section is configured for 2-D airfoil testing. It has four solid walls. The top and bottom walls are flexible and movable whereas the sidewalls are rigid and fixed. The wall adaptation strategy employed requires the test section wall shapes associated with uniform test section Mach number distributions. Calibration tests with the test section empty were conducted with the top and bottom walls linearly diverged to approach a uniform Mach number distribution. Pressure distributions were measured in the contraction cone, the test section, and the high speed diffuser at Mach numbers from 0.20 to 0.95 and Reynolds numbers from 10 to 100 x 10 (exp 6)/per foot

A Survey of Agent-Based Modeling Practices (January 1998 to July 2008)

In the 1990s, Agent-Based Modeling (ABM) began gaining popularity and represents a departure from the more classical simulation approaches. This departure, its recent development and its increasing application by non-traditional simulation disciplines indicates the need to continuously assess the current state of ABM and identify opportunities for improvement. To begin to satisfy this need, we surveyed and collected data from 279 articles from 92 unique publication outlets in which the authors had constructed and analyzed an agent-based model. From this large data set we establish the current practice of ABM in terms of year of publication, field of study, simulation software used, purpose of the simulation, acceptable validation criteria, validation techniques and complete description of the simulation. Based on the current practice we discuss six improvements needed to advance ABM as an analysis tool. These improvements include the development of ABM specific tools that are independent of software, the development of ABM as an independent discipline with a common language that extends across domains, the establishment of expectations for ABM that match their intended purposes, the requirement of complete descriptions of the simulation so others can independently replicate the results, the requirement that all models be completely validated and the development and application of statistical and non-statistical validation techniques specifically for ABM.Agent-Based Modeling, Survey, Current Practices, Simulation Validation, Simulation Purpose

The \u3cem\u3eLex Sempronia Agraria\u3c/em\u3e: A Soldier’s \u3cem\u3eStipendum\u3c/em\u3e

This thesis examines mid-second century BCE Roman society to determine the forces at work that resulted in the passing of a radical piece of legislation known as the lex Sempronia agraria. The advent of this legislation, named for the tribune of the plebs who promulgated it, Tiberius Sempronius Gracchus in 133 BCE, has been heralded as a signal event, a turning point in the Roman Republic that led to revolution and the eventual overthrow of the Republic by Julius Caesar. The historiography up through the twentieth century portrayed this event as a rising of the poor and down-trodden masses against the elite senatorial class of Rome. However, as will be shown, many factors were in play that brought Tiberius Sempronius Gracchus to the acme of his political career and made his lex Sempronia agraria the law of the land. Among these, Roman society was war-weary, having suffered through several military setbacks at the hands of the Spanish, and their legions were being bested by slave armies in Sicily as well. What it meant to be Roman was being continually assaulted under the onslaught of Hellenism through Roman contacts with the Greek east. The economy was shifting from agrarian to a more commercial-centered one. This thesis challenges the simplified notion that this event, the passing of the lex Sempronia agraria came about as a result of class warfare and was the kick-starter to revolution and instead demonstrates that this legislation was in fact, the result, on one hand of a former military officer taking care of the men he had fought alongside, suffered with and eventually brought home to safety and on the other hand came about through the efforts of a plebeian political cabal that recognized the need to incentivize enlistment in a period of low morale amongst the fighting-age men of the Roman Republic