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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Implementing METOC transformation applying autonomous agents

Vorrath, Jonathan J. 09 1900 (has links)
Approved for public release, distribution is unlimited / To achieve integration of the Naval Meteorology and Oceanography (METOC) community into the developing FORCEnet environment, transformational innovations must be researched and implemented. Agent based software is an example of technology that can be employed in this way by changing the method by which METOC data is distributed to end-users. This thesis documents the creation and implementation of a software agent that uses Internet connections to retrieve numerical model data, loads this output into array data containers, and then makes it available to the end-user in a machinereadable forecast object format. The impact of the importation of this forecast object into warfare commander command-and-control software is then assessed using the commercially available SEAWAY logistics tool. This assessment highlights the importance of defining the METOC functional requirements for the emerging FORCEnet environment, so that proper interfaces to exchange data freely, and visually depict it, are incorporated during next generation software development. Using these types of agents to automate the generation and delivery of weather parameters could also allow the importation of data into previously insular software, provide reach-back support to the warfighter, and be a means of reducing manpower and budgetary requirements during this time of fiscal constraint. / Lieutenant, United States Navy
52

A direct thrust measurement system for a waterjet propelled, free running USV

Unknown Date (has links)
The relationship between cross-flow at a waterjet inlet and delivered thrust is not fully understood. A direct thrust measurement system was designed for a waterjet propelled, free running USV. To induce sway velocity at the waterjet inlet, which was considered equivalent to the cross flow, circles of varying radii were performed at Reynolds Numbers between 3.48 x 106 and 8.7 x 106 and radii from 2.7 to 6.3 boat lengths. Sway velocities were less than twenty percent of mean forward speed with slip angles that were less than 20°. Thrust Loading Coefficients were compared to sway as a percent of forward speed. In small radius turns, no relationship was seen, while in larger radius turns, peaks of sway velocity corresponded with drops in thrust, but this was determined to be caused by reduced vehicle yaw in these intervals . Decoupling of thrust and yaw rate is recommended for future research. / Thesis (M.S.)--Florida Atlantic University, 2013.
53

Literature Survey and the Conceptual Design of an Unmanned Arctic Ocean Scientific Vessel

Unknown Date (has links)
In this paper, the possibility of using a Small Water-plane Area Twin Hull (SWATH) as an unmanned Arctic scientific research vessel is analyzed. Before carrying out the stability analysis of the SWATH ship, this paper briefly outlines the importance of the Arctic survey, which guides the importance of the new research ship for Arctic scientific exploration. In addition to being used as a long-tern monitoring and data collection platform, it is also used as a recovery mothership for autonomous equipment such as an AUV. After briefly introducing the basic background of a SWATH, it’s advantages and disadvantages are enumerated and analyzed, and a combination of theoretical and practical tests are used to conduct a brief analysis and summary of the reasons for the appearance of trim by head arising from SWATH navigation. Trim by head occurs when a vessel incline such that its plane of flotation is not coincident with its mean waterline plane. In terms of theory, hydrodynamic equations are used to theoretically deduce the SWATH state of navigation and get the corresponding characteristic equation. Finally, a new type USV be designed conceptionally and be created as a model by Solid-work software. Conceptual design combines the advantages of SWATH and remedy deficiency of its longitudinal stability. The theoretical calculation and analysis of the struts of the conceptual model proves that the oblique struts structure can effectively improves the transverse stability of the model, and with the help of the special slender ellipse structure which is installed on the model’s struts, the righting moment of the model is increased when it’s heeling during a large angle. The hydrodynamic analysis of the conceptual model is carried out by Star- CCM software. The simulation results also prove the effectiveness of stabilizer fins to the longitudinal stability of the conceptual design and reflects the data information of the model in terms of resistance and motion state. At last, we have a general understanding of the performance characteristics of the conceptual model by analysis the feedback data, which provides reliable support for future improvement and optimization. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
54

The dynamics of geometrically compliant mooring systems

Gobat, Jason I January 2000 (has links)
Thesis (Ph. D.)--Joint Program in Applied Ocean Physics and Engineering (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), 2000. / Includes bibliographical references (p. 255-264). / by Jason I. Gobat. / Ph.D.
55

Involvement of cytochrome P450 1A in the toxicity of aryl hydrocarbon receptor agonists : alteration of arachidonic and acid metabolism and production of reactive oxygen species

Schlezinger, Jennifer Joy January 1998 (has links)
Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 1998. / "August, 1998." / Includes bibliographical references (p. 219-254). / Two cytochrome P4501A-dependent mechanisms of aryl hydrocarbon receptor (AhR) agonist toxicity were examined in the marine teleost scup (Stenotomus chrysops), alteration of arachidonic acid (AA) metabolism and production of reactive oxygen species (ROS). In scup hepatic microsomes, cytochrome P450s including CYP1A and CYP2B-like proteins catalyzed regioselective metabolism of AA to eicosatrienoic and hydroxyeicosatetraenoic acids. Benzo[a]pyrene (BP) treatment induced liver microsomal AA metabolism, but that effect varied with season. Endogenous AA epoxides were recovered from scup liver, heart, and kidney, and their composition in the liver was altered by treatment with BP or 2,3,7,8-tetrachlorodibenzo-p-dioxin. In scup and mammals, the formation of ROS was stimulated by binding of 3,3',4,4-tetrachlorobiphenyl (TCB) to CYP1A, apparently CYP1A1. Attack of that ROS inactivated scup CYP1A. ROS release and inactivation of CYPlA were stimulated only by substrates of CYP1A that are slowly metabolized. In vivo, 3,3',4,4',5- pentachlorobiphenyl (PeCB) potently induced CYPlA mRNA, protein and catalytic activity at low doses (0.01-0.1 mg/kg), suppressed induction of CYPlA protein and catalytic activity at a high dose (1 mg/kg) and transiently induced oxidative stress in scup liver. The suppression of CYP1A induction was organ-dependent, with hepatic CYP1A being most susceptible to inactivation. The results suggest that ROS could be involved in the in vivo suppression of scup liver CYP1A by planar halogenated aromatic hydrocarbons. The reactive oxygen sensitive transcription factor, nuclear factor-KB (NF-KB), was characterized in scup. An NF-KB consensus binding sequence bound specifically to 3 proteins in scup liver, heart and kidney. One protein was recognized by an antibody to mammalian p50. Injection alone appeared to activate NF-KB. BP did not increase the activation of NF-KB, and PeCB activated NF-KB in only 1 of 2 experiments. Last, CYP1A induction in endothelial cells of the American eel (Anguilla rostrata), a site which may be particularly susceptible to alterations in AA metabolism and ROS production, was described. Eel liver CYPlA responded to BP, 13-naphthoflavone and TCB in a dose-dependent fashion, and induction was correlated with hepatic inducer concentration. Endothelial CYP1A was inducible in a number of organs and was metabolically active. In the rete mirabile, penetration of endothelial CYP1A induction increased with increasing dose of AhR agonists, corresponding with an increase in inducer concentration. A transition from endothelial to epithelial staining occurred in the gill, heart and kidney at high inducer doses. / by Jennifer Joy Schlezinger. / Ph.D.
56

Physiological and behavioral diagnostics of nitrogen limitation for the toxic dinoflagellate Alexandrium fundyense

Poulton, Nicole Jane, 1970- January 2001 (has links)
Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), February 2001. / Includes bibliographical references. / by Nicole Jane Poulton. / Ph.D.
57

Reproductive traits of pioneer gastropod species colonizing deep-see hydrothermal vents after an eruption

Bayer, Skylar (Skylar Rae) January 2011 (has links)
Thesis (S.M.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2011. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 27-33). / The colonization dynamics and life histories of pioneer species are vital components in understanding the early succession of nascent hydrothermal vents. The reproductive ecology of pioneer species at deep-sea hydrothermal vents may provide insight into their dispersal, population connectivity, and ability to colonize after disturbance. An opportunity to study the reproductive traits of two pioneer gastropod species, Ctenopelta porfera and Lepetodrilus tevnianus, presented itself in 2006 after an eruption on the East Pacific Rise (EPR) eliminated vent communities near 9°50'N. Standard histological techniques were used to determine whether reproductive characteristics, such as timing of gamete release, fecundity, or time to maturation, differed from other vent gastropods in ways that might explain arrival of these two species as early colonizers. Both species exhibited two-component oocyte size frequency distributions that indicated they were quasi-continuous reproducers with high fecundity. In C. porifera, the oocyte size distributions differed slightly between two collection dates, suggesting that environmental cues may introduce some variability in gamete release. In samples collected within one year of the estimated eruption date, individuals in populations of both C. porfera and L. tevnianus were reproductively mature. The smallest reproducing C. porifera were 4.2 mm (males) and 5.4 mm (females) in shell length, whereas reproductive L. tevnianus were smaller (2.3 and 2.4 mm in males and females respectively). Most Cporifera in the population were large (> 6.0 mm) compared to their settlement size and reproductively mature. In contrast, most L tevnianus were small (< 1.0 mm) and immature. Reproductive traits of the two species are consistent with opportunistic colonization, but are also similar to those of other Lepetodrilus species and peltospirids at vents, and do not explain why these particular two species were the dominant pioneers. It is likely that their larvae were in high supply immediately after the eruption due to oceanographic transport processes from remote source populations. / by Skylar Bayer. / S.M.
58

Tidal band current variability over the Northern California continental shelf

Rosenfeld, Leslie Karen January 1987 (has links)
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1987. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND LINDGREN. / Vita. / Includes bibliographies. / by Leslie Karen Rosenfeld. / Ph.D.
59

Behavioral ecology of coral reef fishes at spawning aggregation sites

Sancho, Gorka (Gorka Antonio Sancho-Bizcarrondo), 1968- January 1998 (has links)
Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 1998. / Includes bibliographical references. / by Gorka Sancho. / Ph.D.
60

Diversity and characterization of novel Cytochrome P450 2 genes in the marine teleost Fundulus Heteroclitus

Oleksiak, Marjorie Frances January 1998 (has links)
Thesis (Ph. D.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 1998. / Includes bibliographical references (leaves 179-199). / by Marjorie Frances Oleksiak. / Ph.D.

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