A field investigation of diffusion within a submerged plant canopy

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1997Saltwater marshes and wetlands are important buffers at the land-sea interface. Among the most biologically active ecosystems on Earth, natural and man-made wetlands are important interceptors of pollutants and nutrients bound for the coastal ocean. The transport, dilution, and deposition processes occurring within the marsh are key factors in determining this interception, and these are in turn determined largely by tidally driven flows as influenced by marsh vegetation and other physical characteristics. Vegetation type and density are of primary importance in these processes, both for pollutant/nutrient uptake concerns and in determining hydrodynamic characteristics of the marsh. This study examines the effect of vegetation density and ambient flow on diffusivity within a tidal marsh canopy, specifically Spartina alterniflora. Vegetation densities from 0-1.4% stem coverage and flows from 2-12 cm/sec were investigated using Rhodamine WT tracer, with resultant measured diffusivities ranging from approximately 0.5-3.0 cm2/sec. Diffusivity was found to be a strong function of ambient current, but a much weaker function of vegetation density. Presence of vegetation caused transverse and vertical diffusivities to be essentially isotropic over all vegetation densities, as opposed to the order of magnitude difference found in earlier non-vegetated studies. Only slight vegetation coverage was found to be necessary to produce this isotropy, with little additional change as stem density increased

Agile Development at ABC – What Went Wrong?

Agile development methods continue to enjoy widespread use, with more and more companies transitioning to agile methods.Current literature suggests that most of those companies are successful in making the transition, but others are not sosuccessful. This paper examines one such company – referred to within as the ‘ABC Company’ to maintain their privacy –and analyzes and discusses their struggles with implementing agile methods. In short, it appears that lack of firm leadershipcommitment to agile, absence of a clearly defined customer to provide clearly defined requirements or push for additionalsoftware capabilities, failure to provide adequate initial or ongoing training and support to the organization as a whole, andunderestimating the change management requirements were contributing factors to ABC’s struggles with implementing agilemethods. These conclusions were reached based on a series of interviews with company employees, review of the relevantliterature, and comparisons with other similar case studies

Best Practices for Implementing Agile Methods: A Guide for Department of Defense Software Developers

Traditional plan-driven software development has been widely used in the government because it\u27s considered to be less risky, more consistent, and structured. But there has been a shift from this approach to Agile methods which are more flexible, resulting in fast releases by working in an incremental fashion to adapt to the reality of the changing or unclear requirements. This report describes the Agile software development philosophy, methods, and best practices in launching software design projects using the Agile approach. It is targeted to Defense Department software developers because they face broad challenges in creating enterprise-wide information systems, where Agile methods could be used most effectively. Though not a panacea, agile methods offer a solution to an important class of problems faced by organizations today. Technology and E-Government

Toward Visualization-Specific Heuristic Evaluation

This position paper describes heuristic evaluation as it relates to visualization and visual analytics. We review heuristic evaluation in general, then comment on previous process-based, performance-based, and framework-based efforts to adapt the method to visualization-specific needs. We postulate that the framework-based approach holds the most promise for future progress in development of visualization-specific heuristics, and propose a specific framework as a starting point. We then recommend a method for community involvement and input into the further development of the heuristic framework and more detailed design and evaluation guidelines

Discontinuities and Best Practices in Virtual Research Collaboration

Research collaboration has become increasingly global, as collaboration technologies continue to advance and as research problems become more interdisciplinary and global. Virtual research teams have processes and challenges that are unique from a typical virtual team, and we need a better understanding of how such teams can utilize virtual research environments to their advantage. We examine this question from a review of the relevant literature and an analysis of experiences and reflections from a doctoral seminar that studied and experienced the process of virtual research collaboration

A field investigation of diffusion within a submerged plant canopy

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1997, and Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1997.Includes bibliographical references (leaves 66-69).by Alvin E. Tarrell.M.Eng.M.S

Toward visualization-specific heuristic evaluation

This position paper describes heuristic evaluation as it relates to visualization and visual analytics. We review heuristic evaluation in general, then comment on previous process-based, performance-based, and framework-based efforts to adapt the method to visualization-specific needs. We postulate that the framework-based approach holds the most promise for future progress in development of visualization-specific heuristics, and propose a specific framework as a starting point. We then recommend a method for community involvement and input into the further development of the heuristic framework and more detailed design and evaluation guidelines

Crowdsourcing: A Snapshot of Published Research

Crowdsourcing, originally defined as “taking a job traditionally performed by a designated agent (usually an employee) and outsourcing it to an undefined, generally large group of people in an open call,” is a distributed, collaborative, cross-organizational process seeing increased use among practitioners. As such, crowdsourcing presents great opportunities for information systems (IS) and business-related research. This paper presents preliminary findings from a foundational literature review of published crowdsourcing research from 2006 onward. We identify what crowdsourcing research is going on, where it is going on, and its foci. Our findings document increasing research interest in crowdsourcing and identify the primary publication outlets and home countries of authors involved in that research. Finally, we present a keyword analysis for identified articles, and relate those keywords to a preliminary framework describing crowdsourcing. These findings provide a good summary of current crowdsourcing research, and will help guide researchers interested in further crowdsourcing study