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- Evaluating Ecological Influences of Altered Flow Regimes Using Two- and Three-Dimensional Hydrodynamic ModelsShen, Yi (Virginia Tech, 2009-09-09)Reservoir releases for generating power need to be reconciled with efforts to maintain healthy ecosystems in regulated rivers having irregular channel topography. Fluctuating, complex flow patterns near river obstructions such as boulders and large woody debris provide unique habitat for many aquatic organisms. Numerical modeling of the flow structures surrounding these obstructions is challenging, yet it represents an important tool for aquatic habitat assessment. Moreover, efforts for modeling the morphologically and biologically important transient flows, as well as quantifying their impacts on physical fish habitat during the unsteady-flow period remain rare. In this dissertation, the ability of two- (2-D) and three-dimensional (3-D) hydraulic models to reproduce the localized complex flow features at steady base and peak flows is examined first. The performance of the two hydraulic models is evaluated by comparing the numerical results with measurements of flow around a laboratory hemisphere and boulders located at a reach of the Smith River in Virginia. Close agreement between measured values and the velocity profiles predicted by the two models is obtained outside the wakes behind these obstructions. However, results suggest that in the vicinity of theses obstructions the 3-D model is better suited for reproducing the circulation flow behavior favored by many aquatic species over a broad range of flows. Further, time-dependent flow features affecting channel morphology and aquatic physical habitat are investigated using the numerical models for the same reach in the Smith River. Temporal variation measurements of water surface elevation and velocity profile obtained in the field during a reservoir release are in good agreement with the numerical results. A hypothetical "staggering" flow release scenario simulated by the 3-D model leads to reduced erosional area and longer refugia availability for juvenile brown trout during hydropeaking. Finally, an unsteadiness parameter β is proposed for determining whether an unsteady flow regime can be either modeled using a truly dynamic flow approach or a quasi-steady flow method.
- Food in seventeenth-century Tidewater Virginia: a method for studying historical cuisinesSpencer, Maryellen (Virginia Tech, 1982-06-30)Preface: Knowing how people eat-their foods, preparation styles, and dining customs-helps us understand style of food preparation, a cuisine profile of a culture, the physical how they live. Not merely a is the culinary and gastronomic and behavioral expression of a culture's social and aesthetic values. A cuisine has a dynamic relationship with its time, and historical cuisines also relate to our own time: an understanding of food in history better enables us to interpret and even influence current food styles and patterns. Yet the researcher interested in historical cuisines faces a dilemma: how to conduct historical studies of the subject. Although we have methods for studying the chemical, nutritional, economic, and social aspects of food, we lack methods for studying historical cuisines or for defining the aesthetic and stylistic aspects of a cuisine. Most historical research centered on food has employed agricultural economics in relating food production data to a general nutritional status, while most research on food in culture has studied food habits with the objective of improving nutritional status. American food seems to have been especially neglected in the al ready scanty store of historical food studies, and almost all of the American studies have examined folk or ethnic food. Because so few studies of food history or of cookery styles have been conducted, we lack what might be termed a "body of knowledge." Food history has no orderly scholarly arena, no discipline. One reason for the lack of systematic studies of food in history is an aversion among many scholars in food and nutrition to "cuisines," to the stylistic and aesthetic aspects which might seem merely decorative aspects of man's diet. Another reason is a lack of training among those professionals in humanistic disciplines. But an overriding reason for the absence of scholarly histories of cuisines is the temporal, transitory nature of a cuisine. If we compare cuisines with related popular arts such as costume, textiles, and home furnishings, a distinction quickly emerges: costumes, textiles, but food does not. and furnishings may survive as extant artifacts, However humble or grand, a meal is prepared to be consumed. In no way can we study a meal of the past firsthand; in no way can we know with certainty what tastes, textures, and smells met our ancestors at the dinner table. Descriptions and pictures of a meal reveal no more about a dining experience than descriptions and pictures of a musical event bring us the sounds or the experience of listening. Food in seventeenth-century Virginia serves well as a test subject for a historical method. Historians traditionally have neglected daily life and common people in studies of that period, concentrating instead on politics and the elite. More recently, historical archaeologists and scholars in material culture have begun investigating the realm of daily experience in which food figures importantly, but they have discovered little about the stylistic and aesthetic aspects of the cuisine. This study begins to address those two problems: the need for a method for studying historical cuisines, and the unanswered questions about Virginia's early cuisine. Although the method developed and tested in this study proved complex and demanding, it also brought rewards. Working across disciplines and using three categories of research sources-artifacts, documents, and iconographic records-proved especially helpful in uncovering and sifting data. Much was revealed about the physical context of Virginia's seventeenth-century cuisine: the available foods, the cooking and dining equipage. Aesthetic values were explained to some extent, as were dining customs. But the absence of primary recipe books, the dearth of information about seventeenth-century women, and our general ignorance of daily life during that century hindered discovery of the activities relating to food-the techniques and procedures for preparing, cooking, storing, and serving food. Additional studies, new sources, and refined methods may begin to unlock even those mysteries.
- The Future of Knowledge Creation and Production in University Research Programs and Their Effect on University LibrariesWalters, Tyler (2014-04-11)The dissertation presents possible future directions for research programs at U.S. universities and their effects on the organization of universities and their libraries. The investigator posits four original scenarios produced for this study that describe Grand Challenge-level research program development in U.S. research universities. The scenarios articulate how these universities’ research enterprises might take part in an emerging global research ecosystem that is being shaped by economic, political, cultural, and technological forces. The university managerial leaders involved in research administration can utilize the scenarios in planning for how they might respond to certain forces and drivers effecting the development of their research programs. The leaders, in turn, may understand better the decisions to be made in moving a university forward strategically to realize its goals in the global research environment. The study also examines how the libraries of the participating universities may evolve based on scenario 1, “Thriving interdisciplinary research, solving global Grand Challenges,” which is the scenario most favored by the research directors. Four case studies are offered, produced from interviews with the case library directors. They highlight the directors’ approaches to managerial leadership and organizational culture change with a goal of producing a library that is relevant and vital to its university’s role in the developing global research ecosystem. New library roles are articulated, focusing on managing research outputs, supporting research and scholarly processes, developing technologies and content, and partnering with researchers on research teams and as consultants. The case studies reveal that the more vigorously adapting libraries are differentiated from the lesser adapting libraries according to the level of resources available, technology infrastructures in place, and strategic partnerships created and maintained. This study emphasizes the role of research and library directors in developing and communicating strategic directions to effect change in a U.S. university. Each library director’s response to the favored scenario gives insight into how libraries may approach transformation in the face of momentous change in the university research enterprise due to external drivers. Examining the impact of these drivers through scenarios developed from an institutional perspective aids administrators in planning for how their universities will respond.
- Structural Model Discovery in Temporal Event Data StreamsMiller, Chreston (Virginia Tech, 2013-04-23)This dissertation presents a unique approach to human behavior analysis based on expert guidance and intervention through interactive construction and modification of behavior models. Our focus is to introduce the research area of behavior analysis, the challenges faced by this field, current approaches available, and present a new analysis approach: Interactive Relevance Search and Modeling (IRSM). More intelligent ways of conducting data analysis have been explored in recent years. Ma- chine learning and data mining systems that utilize pattern classification and discovery in non-textual data promise to bring new generations of powerful "crawlers" for knowledge discovery, e.g., face detection and crowd surveillance. Many aspects of data can be captured by such systems, e.g., temporal information, extractable visual information - color, contrast, shape, etc. However, these captured aspects may not uncover all salient information in the data or provide adequate models/patterns of phenomena of interest. This is a challenging problem for social scientists who are trying to identify high-level, conceptual patterns of human behavior from observational data (e.g., media streams). The presented research addresses how social scientists may derive patterns of human behavior captured in media streams. Currently, media streams are being segmented into sequences of events describing the actions captured in the streams, such as the interactions among humans. This segmentation creates a challenging data space to search characterized by non- numerical, temporal, descriptive data, e.g., Person A walks up to Person B at time T. This dissertation will present an approach that allows one to interactively search, identify, and discover temporal behavior patterns within such a data space. Therefore, this research addresses supporting exploration and discovery in behavior analysis through a formalized method of assisted exploration. The model evolution presented sup- ports the refining of the observer\'s behavior models into representations of their understanding. The benefit of the new approach is shown through experimentation on its identification accuracy and working with fellow researchers to verify the approach\'s legitimacy in analysis of their data.