Browsing by Subject "Network"

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Assessment of the demographics and network structure of swine populations in relation to regional disease transmission and contro.
    (2011-06) Wayne, Spencer R
    Commercial swine production has steadily evolved the into interconnected multi-site production systems of today. As a result, large numbers of growing pigs and breeding animals move from one location to another on a daily basis. The health of the national swine herd has improved dramatically, due in large part to this new production structure; but the increased network size and the long distances travelled pose obvious threats to swine health. As animal agriculture has become more sophisticated, our government resources have not kept up. Available datasets are inaccurate, fragmented, and offer limited definition of the population at risk and its nature. National efforts to improve livestock population data have met considerable public resistance, and as a result, progress has been limited. Knowledge of the populations at risk is of primary importance when trying to define the potential for disease to spread within and between these populations. Disease spreads by non-mechanical means (as in aerosol transmission of PRRS virus) potentiates the need for knowledge of the neighborhood. Given the dynamic and transient nature of our swine populations, the neighborhood's health status is constantly challenged by the most recent delivery of pigs into the neighborhood. The following dissertation seeks to expand the knowledge of swine populations. Current geographic datasets were assessed for accuracy and reliability. In the event of a foreign animal disease outbreak the usefulness of these datasets would be of prime importance, as they will dictate the distribution of resources. Additionally, the use of satellite-derived thermal imagery to verify the presence of commercial swine is described, along with its estimated sensitivity and specificity. Any regional disease elimination program must consider all swine populations, therefore non-commercial populations (specifically, 4H exhibition pigs) are analyzed. Population size, seasonality, caretaker knowledge, presumed and measured health status, and relationship with commercial swine are defined. The physical movement of infected animals across the landscape allows rapid spread of a pathogen to occur. Volume, frequency, and geographic scale of movements will dictate how quickly and thoroughly an epidemic will proceed. For this reason, these are defined and displayed for pig producing areas at different scales.
  • Thumbnail Image
    Item
    Assessment of the demographics and network structure of swine populations in relation to regional disease transmission and control.
    (2011-06) Wayne, Spencer R.
    Commercial swine production has steadily evolved the into interconnected multi-site production systems of today. As a result, large numbers of growing pigs and breeding animals move from one location to another on a daily basis. The health of the national swine herd has improved dramatically, due in large part to this new production structure; but the increased network size and the long distances travelled pose obvious threats to swine health. As animal agriculture has become more sophisticated, our government resources have not kept up. Available datasets are inaccurate, fragmented, and offer limited definition of the population at risk and its nature. National efforts to improve livestock population data have met considerable public resistance, and as a result, progress has been limited. Knowledge of the populations at risk is of primary importance when trying to define the potential for disease to spread within and between these populations. Disease spreads by non-mechanical means (as in aerosol transmission of PRRS virus) potentiates the need for knowledge of the neighborhood. Given the dynamic and transient nature of our swine populations, the neighborhood's health status is constantly challenged by the most recent delivery of pigs into the neighborhood. The following dissertation seeks to expand the knowledge of swine populations. Current geographic datasets were assessed for accuracy and reliability. In the event of a foreign animal disease outbreak the usefulness of these datasets would be of prime importance, as they will dictate the distribution of resources. Additionally, the use of satellite-derived thermal imagery to verify the presence of commercial swine is described, along with its estimated sensitivity and specificity. Any regional disease elimination program must consider all swine populations, therefore non-commercial populations (specifically, 4H exhibition pigs) are analyzed. Population size, seasonality, caretaker knowledge, presumed and measured health status, and relationship with commercial swine are defined. The physical movement of infected animals across the landscape allows rapid spread of a pathogen to occur. Volume, frequency, and geographic scale of movements will dictate how quickly and thoroughly an epidemic will proceed. For this reason, these are defined and displayed for pig producing areas at different scales.
  • Thumbnail Image
    Item
    Challenges and design principles of large scale tactical network architecture.
    (2010-12) Peng, Andy Shih-Che
    Modern tactical communications systems are moving towards Internet-style system architectures to support information sharing for improving overall mission effectiveness. Development of such large scale communications systems presents various system design challenges. Research works discussed in this thesis are motivated by the technical challenges commonly encountered during the development of several large scale communications systems and proposes system-level design principles in overcoming these technical challenges. The first part of this thesis addresses system-level quality of service issues by modeling and simulation of an afloat wide area network system architecture. This simulation study investigates the system performance of real-time applications and provides quality of service design recommendations. The second part of this thesis proposes a consolidated network architecture for designing an afloat local area network system. A simulated prototype system is developed to investigate the system performance trade-off in the proposed consolidated network architecture. The third part of this thesis proposes an automatic dynamic resource management system architecture to efficiently manage shared computing resources in resource-constrained network environments without any human operator intervention. Test results in this experimental study demonstrates improved network performance when a communications system employs the automatic dynamic resource management software. Finally, the last part of this thesis proposes a reliable data aggregation and dissemination framework for tactical communications systems operating in disruptive networking environments with intermittent network connectivity. A prototype system is developed and implemented to demonstrate that the proposed framework can ensure reliable data delivery which is beneficial to the current and future development of tactical communications system architectures. This thesis makes several significant research contributions in designing a large scale communications system. First of all, the thesis suggests a simulation methodology for developing simulation models to study the performance of a large scale communications system and makes recommendations on system-level quality of service design. Secondly, the thesis reduces the complexity of future communications system design by proposing a consolidated system architecture. Thirdly, an automatic dynamic resource management software prototype is developed to alleviate resource contention issues commonly found in the tactical networking environments. Fourthly, a reliable data aggregation and dissemination framework is proposed and its function is demonstrated. The proposed framework can accurately infer meaningful messages from a large sensor data set and can reliably deliver the messages to the appropriate network destinations. Finally, the thesis organizes all of these relevant system-level design experiences and recommends system design principles for developing future large scale communications systems.
  • Thumbnail Image
    Item
    Governance of academic planning in public higher education systems
    (2013-03) Harmening, Todd R.
    The recent interest in harnessing the collective capacity of public institutions of higher education is challenging long-held beliefs about system coordination. Constricted state resources, globalization, market forces, and new technologies suggest that new governance structures are not only a necessity but an opportunity to better connect system institutions. To build such collective capacity, public systems will be well-served to adopt new forms of governance and challenge historic or misaligned policies and activities. The purpose of this study was to examine the primary means by which system office staff coordinate institutional activities within academic planning. The study was constructed around identification of bureaucratic, market, and network practices in selected governing board systems to better understand the existing system policies and staff activities, as well as the shifts and associated challenges being experienced in the system governance of academic planning. The population for this study included six state systems of higher education consisting of 2- and 4-year institutions. An initial document analysis of state statutes, system policies, and recent system reports provided a base understanding of the policies and other factors driving each system’s academic planning activities. A subsequent survey of system chief academic officers and their staff identified the importance of the policy elements, associated activities, and critical stakeholders for system academic initiatives, and program approval and review. The subsequent interviews of survey respondents explored the context and meanings associated with the survey responses, as well as challenges and future shifts in the approaches to system academic planning. The findings and conclusions from the study suggest that system policies for program approval and associated system office staff activities are predominantly, if not exclusively, focused on system expectations of individual institutions with some limited but notable examples of interinstitutional program collaboration. Similarly, system office staff face significant challenges in simultaneously building collaborative capacity and balancing the policy interests of state policymakers, national organizations, and industry with the academic culture and local autonomy of system institutions. The state systems in the study noted recent and substantial shifts in system governance of academic planning resulting from enactment of state or system initiatives for degree completion, removal of bureaucratic elements that slow system processes, and/or delegation of more authority to system institutions. In addition, system office academic affairs staff noted their substantial interest and role in facilitating academic collaboration across institutions. Most of the state systems in the study are in the early stages of or stated interest in elevating support for interinstitutional collaboration, including changes to system policies, merging of administrative structures, and development of collaborative agreements to support interinstitutional activity. The study also indicates that system office staff are facing significant challenges in engaging faculty in collaborative activity across multiple and loosely coupled levels of administration. Significant shifts in system policies and staff activities are necessary to remove or better align the predominance of bureaucratic and market mechanisms with system efforts at academic collaboration. System leaders would be well served in engaging their institutional faculty and administration in casting a vision and clearing the way for network capacity to emerge.
  • Thumbnail Image
    Item
    Network morphologies in monodisperse and polydisperse multiblock terpolymers.
    (2009-02) Meuler, Adam James
    Multiply continuous network morphologies were previously identified in “monodisperse” (polydispersity index (PDI) < ~1.1 in all blocks) poly(isoprene-bstyrene- b-ethylene oxide) (ISO) triblock terpolymers. This work extends the investigation of multiply continuous network structures to two other classes of multiblock terpolymers: i) “monodisperse” OSISO pentablocks and ii) polydisperse ISO triblocks. The OSISO pentablocks are synthesized using a protected initiation strategy that required the development of the functional organolithium 3-triisopropylsilyloxy-1- propyllithium (TIPSOPrLi). TIPSOPrLi may be used to prepare α-hydroxypolystyrene with narrower molecular weight distributions (PDI ~ 1.1) than are attainable using the commercially available 3-tert-butyldimethylsilyloxy-1-propyllithium. A telechelic triblock terpolymer (HO-SIS-OH) with narrow molecular weight distributions in all blocks is prepared using TIPSOPrLi. A series of OSISO pentablocks is synthesized from this parent triblock, and a stable region of O70 (the orthorhombic Fddd network) is identified between two-domain lamellae (LAM2) and three-domain lamellae (LAM3) in OSISO materials. This sequence of morphologies was previously reported in ISO triblocks with comparable compositions. Mechanical tensile testing reveals that an OSISO sample with a lamellar mesostructure fractures in a brittle fashion at a strain of 0.06. An OSISO containing the O70 network, in contrast, has a strain at failure of 1.3, even though the crystallinity of the terminal blocks is above the brittle threshold established in other multiblock materials. This improved toughness is attributed to the combined effects of a triply continuous morphology and an intrinsically tough SIS core. The ISO triblock studies probe the stability of network morphologies with respect to polydispersity in the polystyrene and poly(ethylene oxide) chains. Three series of ISO triblocks with polydisperse (PS PDI = 1.16, 1.31, 1.44) polystyrene blocks are prepared by anionic polymerization. While the network “window” in the PS PDI = 1.16 series is comparable in width and location to the window reported in the “monodisperse” ISO materials, it apparently shrinks for the higher PS PDI values. Only lamellar mesostructures are reported in the PS PDI = 1.31 materials, and network morphologies are identified over only a narrow range of compositions in the PS PDI = 1.44 samples. Polydispersity does not always destabilize network morphologies, however, as broadening the molecular weight distribution of the terminal poly(ethylene oxide) block drives a morphological transition from lamellae to the coreshell gyroid network. This result demonstrates that polydispersity can be used to tune block terpolymer phase behavior and stabilize technologically useful network mesostructures. Self-consistent field theory calculations augment the experimental analysis and offer insight into the physics underlying the polydispersity-driven morphological changes.
  • Thumbnail Image
    Item
    The politics of ethical witnessing: the participatory networks of 9/11 Media Culture
    (2010-09) Wessels, Emanuelle
    This dissertation examines the politics of ethical witnessing in three genres of convergent media that overtly or allegorically address the events of September 11th. These include a conspiracy theory documentary, the Hollywood monster movie Cloverfield, and the documentary film Control Room. Using a combination of psychoanalytic film and political theory, ethical philosophy, and scholarship on mediated networks and media convergence; I argue, through these case studies, that the ways in which films today interact with participatory media such as websites and video playlists carry particular implications for the ethical and political aspects of how spectators are positioned to watch, interact with, and "talk back" to the media they consume.
  • Thumbnail Image
    Item
    Reconstructing Past Craft Networks: A Case Study using 3D scans of Late Bronze Age Swords to reconstruct Specialized Craft Networks
    (2016-05) Golubiewski-Davis, Kristina
    As the collection of 3d data proliferates in the archaeological community, new methods integrating analysis of those data must also be developed. This dissertation project approaches the problem of observing social networks by examining decisions made by specialized craft workers: specifically, Late Bronze Age smiths (~1200-800BC). The data examined include shape data collected from 3D scans of bronze swords. These data were used to group the blades using cluster analysis based on different aspects of the swords including blade profile, hilt profile, and various decorative shape data. Those clusters create links between the swords which were then used to examine the network of bronze smiths. This project is a case study of how one might go about studying the way individuals with specialized knowledge were connected in the past by studying the results of that knowledge expressed through tangible differences between artifacts.
  • Thumbnail Image
    Item
    Seeing both the trees and the forest: an analysis of the Indian interorganizational network.
    (2010-08) Mani, Dalhia
    Economic sociology and organizational theory propose that economic activity is structurally embedded. Structural embeddedness refers to the fact that actors' actions and outcomes are affected by the overall structure of ties in which the actor resides. However, current interpretations of this concept are fairly narrow, and focus on the structure of the immediate network of ties. The assumption is that beyond the first-level of contacts, the structure of ties does not matter. My dissertation broadens the current conception of structural embeddedness to include the structure of second-level contacts, third-level contacts (and so on), until the structure of the overall network of ties is taken into account. I apply this concept of structural embeddedness in the overall network to the network, group, and firm level of analysis. My study is based on the network of publicly traded firms in India. At the level of the network, current theory predicts that interorganizational networks are small worlds, with dense clusters connected to each other with sparse ties. However, research on cross-national differences in organizational activity suggests dense clusters of firms embedded in dense networks of ties, a pattern more consistent with a nested world. I find that the Indian interorganizational network is a hybrid, with portions of the network displaying a small world, nested world, and atomized structure. Firms reside within different social structures, and this research suggests the importance of meso-level variation in firms' social structure. At the level of the group, current business group theory assumes that business groups are large and entrenched within a network of ties. Contrary to this prediction, a focus on structural embeddedness in the overall network suggests that Indian business groups vary widely in their position in relation to the rest of the network, and the large majority of Indian business groups are small and isolated. Finally, at the level of the individual firm, I find that structural embeddedness within the overall network is consequential, and significantly affects firm performance, even after controlling for other firm, industry, group, and network characteristics.