Cellular automata study of the feasibility of a parallel optical computer

The speed of modern electronic computers has inherent design limitations which will soon be reached. A possible substitute is the optical computer. In this project, the feasibility of the optical computer is explored by designing and building a parallel optical system. This system is used to test the basic principles that would govern a parallel optical computer. The system is based on the principle of cellular automata, which is a simulation technique used to study interactions of objects in a system. The following goals were set. The system would be based on cellular automata. A one-dimensional array with nine cells, or data bits, in the array would be studied. The transition rules governing how the data is modified would be easy to change. Finally, the system would be as fully optical as possible, with electrical counterparts allowed as needed. These goals help steer the direction of the design, and are discussed in this thesis. The design is built, and test data is introduced to determine proper operation of the system --Abstract, page ii

Think You Know Ketchup, Think Again

This project was submitted in partial fulfillment of the requirements for the Master of Science in Journalism degree

Who Is a Social Worker?

Defining social workers for the purposes of research is not as straightforward as it sounds. To date, researchers who have examined social workers as a group have used a variety of sampling methods. Multiple methods speak to the variety of options for defining social workers. Understanding membership within the profession is a precondition to understanding research about the behavior of those within the profession. This research note explores these sampling methods in detail. Each has its advantages, but none are without their own disadvantages, some of which bias their view of the profession. As researchers who have considered the political behavior of social workers, we consider six methods for sampling social workers that have been used to understand their behavior in this specific domain. Importantly, the sampling methods examined here can be applied to research about social workers outside of politics. These include sampling (1) members of professional organizations, (2) licensed social workers, (3) social work students, (4) graduates of social work programs, (5) social work faculty, and (6) members of social work-related occupations. After reviewing the advantages and disadvantages of each, we provide scholars a table for reference. The authors recommend that the Council on Social Work Education, National Association of Social Workers, and several other professional associations pull together members to explore a unified definition of social work through integrated practice and refrain from focusing on what makes us different

Estimating Foreign-Object-Debris Density from Photogrammetry Data

Within the first few seconds after launch of STS-124, debris traveling vertically near the vehicle was captured on two 16-mm film cameras surrounding the launch pad. One particular piece of debris caught the attention of engineers investigating the release of the flame trench fire bricks. The question to be answered was if the debris was a fire brick, and if it represented the first bricks that were ejected from the flame trench wall, or was the object one of the pieces of debris normally ejected from the vehicle during launch. If it was typical launch debris, such as SRB throat plug foam, why was it traveling vertically and parallel to the vehicle during launch, instead of following its normal trajectory, flying horizontally toward the north perimeter fence? By utilizing the Runge-Kutta integration method for velocity and the Verlet integration method for position, a method that suppresses trajectory computational instabilities due to noisy position data was obtained. This combination of integration methods provides a means to extract the best estimate of drag force and drag coefficient under the non-ideal conditions of limited position data. This integration strategy leads immediately to the best possible estimate of object density, within the constraints of unknown particle shape. These types of calculations do not exist in readily available off-the-shelf simulation software, especially where photogrammetry data is needed as an input

Clinical Social Workers, Gender, and Perceptions of Political Participation

Political participation to create social change is considered a professional and ethical imperative for social workers. Although researchers have examined overall political participation by social workers, little is known about how clinical social workers participate and the broader societal factors that influence their political participation. A critical phenomenological methodology was used with a sample of 23 clinical social workers from New England states to (1) identify how socio-political forces influenced their political activity; and, (2) understand how the concept of power affected individuals’ level of engagement or inclination toward the political process. This article describes one of the study’s major findings. Female participants described themselves as unqualified and/or unknowledgeable in the political sphere, with low levels of ambition and confidence to engage in political processes. Many female participants also described the challenges of achieving a work-life balance between their careers and traditional gender-based roles with little time left for political engagement. Social work education and policy advocacy can affect change that will increase the internal and external efficacy of social workers and create a policy environment that allows more options for all social workers in balancing the demands of professional and personal lives

A Modification and Analysis of Lagrangian Trajectory Modeling and Granular Dynamics of Lunar Dust Particles

A previously developed mathematical model is amended to more accurately incorporate the effects of lift and drag on single dust particles in order to predict their behavior in the wake of high velocity gas flow. The model utilizes output from a CFD or DSMC simulation of exhaust from a rocket nozzle hot gas jet. An extension of the Saffman equation for lift based on the research of McLaughlin (1991) and Mei (1992) is used, while an equation for the Magnus force modeled after the work of Oesterle (1994) and Tsuji et al (1985) is applied. A relationship for drag utilizing a particle shape factor (phi = 0.8) is taken from the work of Haider and Levenspiel (1989) for application to non-spherical particle dynamics. The drag equation is further adjusted to account for rarefaction and compressibility effects in rarefied and high Mach number flows according to the work of Davies (1945) and Loth (2007) respectively. Simulations using a more accurate model with the correction factor (Epsilon = 0.8 in a 20% particle concentration gas flow) given by Richardson and Zaki (1954) and Rowe (1961) show that particles have lower ejection angles than those that were previously calculated. This is more prevalent in smaller particles, which are shown through velocity and trajectory comparison to be more influenced by the flow of the surrounding gas. It is shown that particles are more affected by minor changes to drag forces than larger adjustments to lift forces, demanding a closer analysis of the shape and behavior of lunar dust particles and the composition of the surrounding gas flow

Photogrammetry and ballistic analysis of a high-flying projectile in the STS-124 space shuttle launch

A method combining photogrammetry with ballistic analysis is demonstrated to identify flying debris in a rocket launch environment. Debris traveling near the STS-124 Space Shuttle was captured on cameras viewing the launch pad within the first few seconds after launch. One particular piece of debris caught the attention of investigators studying the release of flame trench fire bricks because its high trajectory could indicate a flight risk to the Space Shuttle. Digitized images from two pad perimeter high-speed 16-mm film cameras were processed using photogrammetry software based on a multi-parameter optimization technique. Reference points in the image were found from 3D CAD models of the launch pad and from surveyed points on the pad. The three-dimensional reference points were matched to the equivalent two-dimensional camera projections by optimizing the camera model parameters using a gradient search optimization technique. Using this method of solving the triangulation problem, the xyz position of the object's path relative to the reference point coordinate system was found for every set of synchronized images. This trajectory was then compared to a predicted trajectory while performing regression analysis on the ballistic coefficient and other parameters. This identified, with a high degree of confidence, the object's material density and thus its probable origin within the launch pad environment. Future extensions of this methodology may make it possible to diagnose the underlying causes of debris-releasing events in near-real time, thus improving flight safety.Comment: 26 pages, 11 figures, 3 table