Seismic refraction tomography is an alternative to conventional seismic refraction analysis methods. While the limitations and potential pitfalls of conventional refraction methods are wellknown the same is not true for refraction tomography. As refraction tomography becomes more widely used, the need to know and understand its capabilities as well as its limitations becomes more critical. In this study we created eight representative models for use in evaluating three commercially available codes as well as refraction tomography in general. These models range from simple two-layer or dipping-layer problems to more complicated models designed to represent features of karst terrains. We demonstrate quantitatively and qualitatively that all three codes perform at a similar level, although each has strengths and weaknesses. Refraction tomography performs well in many situations where conventional methods fail, e.g., where lateral or vertical gradients compose a significant component of the velocity structure.

The concept of complexity is a popular and contentious topic. Just what is complexity? What does it mean to 'think complexly'? This paper addresses both of these issues. Complexity thinking is impossible to define with any precision as it deals not only with change, dynamic change, evergoing, but with transformative change. Definitions require stability, the very element complexity neither has nor aspires to have. Instead complexity asks us to see, to deal with a world in continual flux; but a world that does have patterns to it, patterns that bind and structure through their interplay. In short, complexity seeing/thinking asks us to envision our world and events within that world in terms, not of 'things' but of process. In so doing, we are moving from a science that studies particles to the new sciences of chaos and complexity that study the interactive relations between and among particles, events, happenings. After distinguishing the similarities and contrasts between chaos and complexity, and showing the characteristics of each, along with looking at systems closed and open, frames modern and post-modern, this paper enumerates practical aspects of thinking complexly: accepting ambiguity, allowing humility to permeate one's being, and seeking out and utilizing difference and diversity. The health care profession by its very nature of dealing with that which is dynamically living deals with the complex daily. Its routines and rules, though, are too often caught in a modernist trap. This paper challenges all health care professionals to break free from that trap, and suggests ways to do so.

This paper has two main foci: (1) the history of curriculum design, and (2) implications from the new sciences of chaos and complexity for the development of new forms of curriculum design and teaching implementation. Regarding the first focus, the paper posits that there exist-to use Wittgenstein's phrase-'family resemblances' between Peter Ramus' 16 th century curriculum design and that of Ralph Tyler in the 20 th century. While this 400-year linkage is by no means linear, there are overlapping strands from Ramus to Comenius to the Puritans to colonial New England to Horace Mann to Ralph Tyler. What unites these strands, all belonging to the Protestant Methodization movement that swept across northern Europe into colonial America and the USA, is the concept of Method. Taylor's 'time and motion' studies set the stage for Tyler's Basic Principles of curriculum design-those starting with set goals and concluding with measured assessment. The second focus draws on the new sciences of chaos and complexity to develop a different sense of curriculum and instruction-open, dynamic, relational, creative, and systems oriented. The paper concludes with an integration of the rational/scientific with the aesthetic/ spiritual into a view of education and curriculum informed by complexity.Curriculum, as we know it, has always had a culture: Protestant. That is, since John Calvin in the mid-1500s appropriated the word, obviously Latin in origin, to mean a course, or path, of life (curriculum vitae), instead of a racetrack around which chariots sped (OED online, 2005), the word and concept of curriculum have been embedded in a Protestant, bourgeois, commercial/capitalist culture. 1 The word curriculum, in our educational sense of 'a regular course of study or training, as at a school or university', leading to a degree or certification (OED online, 2005), was first used by a Peter Ramus (Petrus Ramus)--schoolmaster, headmaster, Regius Professor of Logic--in the late 16 th century. 2 Ramus' ordering of courses, indeed, all knowledge, is shown in the following Ramist map (or chart).The word curriculum appears in the center left, classifying and organizing the Seven Liberal Arts as part of the work of philosophy. 3 Prior to such a graphic representation, studies of the trivium (grammar, dialectic, rhetoric) and quadrivium (arithmetic, geometry, physics and ethics or music) were more loosely organized

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Improved surface-based geophysical technologies that are commercially available provide a new level of detail that can be used to guide ground water remediation. Surface-based multielectrode resistivity methods and tomographic seismic refraction techniques were used to image to a depth of approximately 30 m below the surface at the Natural and Accelerated Bioremediation Research Field Research Center. The U.S. Department of Energy (DOE) established the research center on the DOE Oak Ridge Reservation in Oak Ridge, Tennessee, to conduct in situ field-scale studies on bioremediation of metals and radionuclides. Bioremediation studies are being conducted on the saprolite, shale bedrock, and ground water at the site that have been contaminated with nitrate, uranium, technetium, tetrachloroethylene, and other contaminants (U.S. DOE 1997). Geophysical methods were effective in imaging the high-ionic strength plume and in defining the transition zone between saprolite and bedrock zones that appears to have a significant influence on contaminant transport. The geophysical data were used to help select the location and depth of investigation for field research plots. Drilling, borehole geophysics, and ground water sampling were used to verify the surface geophysical studies.

Seismic refraction methods are used in environmental and engineering studies to image the shallow subsurface. We present a blind test of inversion and tomographic refraction analysis methods using a synthetic first-arrival-time dataset that was made available to the community in 2010. The data are realistic in terms of the near-surface velocity model, shot-receiver geometry and the data's frequency and added noise. Fourteen estimated models were determined by ten participants using eight different inversion algorithms, with the true model unknown to the participants until it was revealed at a session at the 2011 SAGEEP meeting. The estimated models are generally consistent in terms of their large-scale features, demonstrating the robustness of refraction data inversion in general, and the eight inversion algorithms in particular. When compared to the true model, all of the estimated models contain a smooth expression of its two main features: a large offset in the bedrock and the top of a steeply dipping low-velocity fault zone. The estimated models do not contain a subtle low-velocity zone and other fine-scale features, in accord with conventional wisdom. Together, the results support confidence in the reliability and robustness of modern refraction inversion and tomographic methods.

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This paper has two main foci: (1) the history of curriculum design, and (2) implications from the new sciences of chaos and complexity for the development of new forms of curriculum design and teaching implementation. Regarding the first focus, the paper posits that there exist—to use Wittgenstein’s phrase—‘family resemblances’ between Peter Ramus’ 16th century curriculum design and that of Ralph Tyler in the 20th century. While this 400-year linkage is by no means linear, there are overlapping strands from Ramus to Comenius to the Puritans to colonial New England to Horace Mann to Ralph Tyler. What unites these strands, all belonging to the Protestant Methodization movement that swept across northern Europe into colonial America and the USA, is the concept of Method. Taylor’s ‘time and motion’ studies set the stage for Tyler’s Basic Principles of curriculum design—those starting with set goals and concluding with measured assessment. The second focus draws on the new sciences of chaos and complexity to develop a different sense of curriculum and instruction—open, dynamic, relational, creative, and systems oriented. The paper concludes with an integration of the rational/scientific with the aesthetic/ spiritual into a view of education and curriculum informed by complexity.