• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 1
  • Tagged with
  • 10
  • 6
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Revisão taxonômica das espécies do gênero Sphyraena Röse, 1793 (Teleostei, Perciformes, Sphyraenidae) ocorrentes na costa leste da América do Sul / Taxonomic revision of the species of Sphyraena Röse, 1793 (Teleostei, Perciformes, Sphyraenidae) from eastern coast of South America

Lopes , Paulo Roberto Duarte 01 October 1997 (has links)
Submitted by Alberto Vieira (martins_vieira@ibest.com.br) on 2018-06-14T18:47:27Z No. of bitstreams: 1 278394.pdf: 4225737 bytes, checksum: ea712086dc321f4440d1fc150b87c227 (MD5) / Made available in DSpace on 2018-06-14T18:47:27Z (GMT). No. of bitstreams: 1 278394.pdf: 4225737 bytes, checksum: ea712086dc321f4440d1fc150b87c227 (MD5) Previous issue date: 1997-10-01 / CAPES / Com base em material procedente da costa do Estado do Ceará ( cerca de 04º00'S - 39º00'W) e Santa Catarina (cerca de 29º00'S - 49°00'W), procedeu-se à revisão taxonômica das espécies do monotípico gênero Sphyraena Röse, 1793 (Teleostei, Perciformes, Sphyraenidae) ocorrentes em águas brasileiras. Sinônimos de material citado do Brasil, diagnoses e informações sobre padrões de coloração, distribuição e habitat preferencial são dados para cada espécie. Uma chave de identificação para as espécies reconhecidas é apresentada. São reconhecidas para o Brasil as espécies S. barracuda(Walbaum, 1792) - que ocorre ao longo de todo o litoral e ainda nas quatro ilhas oceânicas brasileiras -, S. guachancho Cuvier, 1829 - que ocorre ao longo de todo o litoral -, S. sphyraena (Linnaeus, 1758) - conhecida de um único exemplar procedente de Cabo Frio (cerca de 23º00'S - 42º00'W) - e S. borealis De Kay, 1842 - que ocorre ao longo de todo o litoral brasileiro e da qual S. tome Fowler, 1903 é considerada sinônimo júnior. S. picudilla Poey, 1860, citada para o Brasil, não foi identificada entre o material examinado e aparentemente não ocorre em águas brasileiras. S. branneri Ribeiro, 1915, descrita de um único exemplar procedente do Estado de Pernambuco (cerca de 08º00'S - 35º00'W) é sinônimo júnior de S. Guachancho. / A taxonomic revision of the species of the genus Sphyraena Röse, 1793 (Teleostei, Perciformes, Sphyraenidae) occurring in eastern coast of South America waters is presented. The study was based on specimens obained along the coast from off the State of Ceará (about 04º00'S - 39º00'W) to Santa Catarina (about 29º00'S - 49º00'W). Synonyms cited from Brazil, diagnosis, and notes on colour patterns, distribution and habitat are included for each species. A key for the species which occur in Brazil is presented. The following species are recognized from eastern coast of South America waters: S. barracuda (Walbaum, 1792) - which occurs along the coast and the four oceanic islands of Brazil -, S. guachancho Cuvier, 1829 - which occurs along the entire coast -, S. sphyraena (Linnaeus, 1758) - known from a single specimen from Cabo Frio (about 23º00'S - 42°00'W) -, and S. borealis De Kay, 1842 - which occurs along the entire coast and of which S. tome Fowler, 1903 is a junior synonym. S. picudilla Poey, 1860, recorded from Brazil, has not been identified among the material examined and apparently does not occur in Brazilian waters. S. branneri Ribeiro, 1915, described from a single specimen from the State of Pernambuco (about 08º00'S - 35º00'W) is considered a junior synonym of S. guachancho.
2

Developing a Neural Network Model for Semantic Segmentation / Utveckling av en neural nätverksmodell för semantisk segmentering

Westphal, Ronny January 2023 (has links)
This study details the development of a neural network model designed for real-time semantic segmentation, specifically to distinguish sky pixels from other elements within an image. The model is incorporated into a feature for an Augmented Reality application in Unity, leveraging Unity Barracuda—a versatile neural network inference library. While Barracuda offers cross-platform compatibility, it poses challenges due to its lack of support for certain layers and operations. Consequently, it lacks the support of most state-of-the-art models, and this study aims to provide a model that works within Barracuda.  Given Unity's absence of a framework for model development, the development and training of the model was conducted in an open-source machine learning library. The model is continuously evaluated to optimize the trade-off between prediction accuracy and operational speed.   The resulting model is able to predict and classify each pixel in an image at around 137 frames per second. While its predictions might not be on par with some of the top-performing models in the industry, it effectively meets its objectives, particularly in the real-time classification of sky pixels within Barracuda. / Denna rapport beskriver utvecklingen av en neural nätverksmodell avsedd för semantisk segmentering i realtid, specifikt för att särskilja himlen från andra element inom en bild. Modellen integreras i en funktion för en applikation med augmenterad verklighet i Unity, med hjälp av Unity Barracuda - ett mångsidigt bibliotek för neurala nätverk. Även om Barracuda erbjuder kompatibilitet över olika plattformar, medför det utmaningar på grund av dess brist på stöd för vissa lager och operationer. Följaktligen saknar den stöd från de bäst presterande modellerna, och denna studie syftar till att erbjuda en modell som fungerar inom Barracuda. Med tanke på Unitys avsaknad av ett ramverk för modellutveckling valdes ett open-source maskininlärningsbibliotek. Modellen utvärderas kontinuerligt för att optimera avvägningen mellan förutsägelseprecision och driftshastighet. Den resulterande modellen kan förutsäga och klassificera varje pixel i en bild med en hastighet på cirka 137 bilder per sekund. Även om dess förutsägelseprecision inte är i nivå med några av de bäst presterande modellerna inom branschen, uppfyller den effektivt sina mål, särskilt när det gäller realtidsklassificering av himlen inom Barracuda.
3

Utveckling av ett administrativt webbgränssnitt i ramverket Struts / The development of an administrative web interface in the Struts framwork

Wiremark, Pär January 2004 (has links)
<p>The purpose of this report has been to develop an administrative web interface. The web interface is to be used by the company Zidango and it is going to make it easier for them in their daily work of running a web portal. The interface had to be developed so it would fit in Zidangos web portal. This meant the work had to be done in the framwork Struts and mostly in JAVA. Thereforeis a shorter theory chapter included in the report that discusses frameworks. In addition to the theory chapter the report describes the development of the interface, the solution and thoughts around it.</p>
4

Utveckling av ett administrativt webbgränssnitt i ramverket Struts / The development of an administrative web interface in the Struts framwork

Wiremark, Pär January 2004 (has links)
The purpose of this report has been to develop an administrative web interface. The web interface is to be used by the company Zidango and it is going to make it easier for them in their daily work of running a web portal. The interface had to be developed so it would fit in Zidangos web portal. This meant the work had to be done in the framwork Struts and mostly in JAVA. Thereforeis a shorter theory chapter included in the report that discusses frameworks. In addition to the theory chapter the report describes the development of the interface, the solution and thoughts around it.
5

Feeding Ecology and Habitat Utilization of the Great Barracuda Sphyraena barracuda (Edwards 1771) in Southeast Florida

Hansen, Noah R. 01 January 2015 (has links)
Great barracuda Sphyraena barracuda is a large predatory teleost found circumglobally, other than the Eastern Pacific Ocean. The species is commonly caught by both recreational and commercial fishermen as bycatch while targeting other, more economically or recreationally valuable fishes. This species also exhibits an ontogenetic shift in habitat, with juveniles inhabiting mangrove and seagrass habitats, while adults live near offshore reefs and associated structure. This thesis consists of two separate studies of S. barracuda: 1) feeding ecology along an ontogenetic gradient and 2) habitat utilization of as derived through electronic tagging. The first chapter of this thesis describes the feeding ecology of great barracuda in South Florida, with an emphasis on the determination of when the ontogenetic shift in diet occurs between habitats and individual fish sizes. Specimens were collected primarily by seine net and hook-and-line fishing. The specimens were then dissected with the stomach contents examined. This study found that the ontogenetic diet shift in great barracuda begins around the second year, and that juveniles and adults are opportunistic predators with a wide diversity of teleost and crustacean prey items within the selected habitat. The second chapter of this thesis describes the habitat utilization and vertical movements of two great barracuda off of South Florida interpreted from data acquired from pop-up satellite archival tags (PSATs). This study found that large (>100 cm) great barracuda are capable of travelling hundreds of kilometers over a period of days to weeks. The results show that large great barracuda can tolerate temperatures ranging from 17.8° C to 31.3° C, and are capable of diving to depths greater than 175 m. It was also found that there was a significant difference in time spent at depth, with greater depths being inhabited more frequently at night.
6

Les rides de Barracuda et de Tiburon, à l'Est de la subduction des Petites Antilles : origine, évolution et conséquences géodynamiques / The Barracuda Ridge and Tiburon Rise, East of the Lesser Antilles : origin, evolution and geodynamic implications

Pichot, Thibaud 18 June 2012 (has links)
Les rides de Barracuda et de Tiburon sont deux reliefs sous-marins situés dans la partie ouest de l'océan Atlantique, là où la lithosphère océanique des plaques Amérique du Nord (NAM) et Amérique du Sud (SAM) est entraînée par subduction sous la plaque Caraïbe, formant l'arc volcanique des Petites Antilles et le prisme d’accrétion de Barbade. Le processus et la période de soulèvement conduisant au relief actuel de ces rides (qui semblent être un marqueur important dans l'histoire géodynamique de la région) sont sujets à débat depuis des décennies.L’interprétation de nouvelles données de sismique réflexion et de bathymétrie multifaisceaux acquises à travers les rides de Barracuda et de Tiburon (campagne Antiplac, 2007 ) a permis de dater les périodes de soulèvements des rides et réaliser des reconstructions paléogéographiques incluant les flux sédimentaires majeurs, depuis le Crétacé jusqu’ à l’Actuel.L’analyse structurale révèle des phases de réactivations tardives d’anciennes zones de fractures dans un contexte transpressif, conduisant aux surrections des rides de Tiburon et de Barracuda.Les processus géologiques possibles impliqués dans la formation des rides de Barracuda et de Tiburon coïncident avec les modèles cinématiques récents décrivant les mouvements relatifs entre les plaques NAM et SAM, le long de la limite de plaque diffuse.Ces résultats permettent de mieux définir la limite de plaque entre NAM et SAM. Elle est nécessairement hétérogène exploitant les zones de faiblesses dans la lithosphère que sont les zones de fracture. Au sein de cette limite de plaque la lithosphère serait donc fragmentée. / The Barracuda Ridge and the Tiburon Rise, two oceanic-basement ridges, lie in the western Atlantic Ocean, where oceanic lithosphere of the North American (NAM) and South American (SAM) plates is subducted beneath the Caribbean plate, creating the Lesser Antilles volcanic arc and the Barbados Ridge accretionary complex. The process and the timing of the uplift leading to the present day morphologies of the Tiburon and Barracuda ridges, that seem to be key markers in the geodynamic history of the region, has remained a matter of debate for decades.From the analysis of new multibeam and seismic reflection profiles acquired in 2007 (Antiplac crusie) DSDP-ODP boreholes available, we provide new information on the timing of the formation of the Barracuda Ridge and Tiburon Rise in their present-day configurations. We propose paleogeographic reconstructions with the main sediments fluxes deposited in the area of the Barracuda and Tiburon ridges from the Late Cretaceous to present. Structural analysis shows reactivation of fracture zones in a transpressive setting leading to the uplifts of the Barracuda and Tiburon Ridges.The location of the Barracuda Ridge and the Tiburon Rise and the timing of the uplift fit well with recent global plate kinematic models describing the movements of NAM relative to SAM along a diffuse plate boundaryThis NAM-SAM plate boundary zone, therefore must most certainly be heterogeneous in nature, exploiting weaknesses in the lithosphere provided by fracture zones where mechanically advantageous, but forming new boundary segments elsewhere, to transfer motion between reactivated segments of the fracture zones.
7

Spatial Ecology of Great Barracuda (Sphyraena barracuda) around Buck Island Reef National Monument, St. Croix, U.S.V.I.

Becker, Sarah L 13 July 2016 (has links) (PDF)
Marine protected areas (MPAs) are increasing in popularity as a tool to manage fish stocks through conservation of entire habitats and fish assemblages. Quantifying the habitat use, site fidelity, and movement patterns of marine species is vital to this method of marine spatial planning. The success of these protected areas requires that sufficient habitat is guarded against fishing pressure. For large animals, which often have correspondingly large home range areas, protecting an entire home range can be logistically challenging. For MPAs to successfully protect large top predator species, it is important to understand what areas of a home range are especially important, such as breeding and feeding grounds. New technologies, such as acoustic telemetry, have made it possible to track marine animal movements at finer spatial and temporal scales than previously possible, better illuminating these spatial use patterns. This study focused on the movement patterns of great barracuda (n=35), an ecologically important top predator, around Buck Island Reef National Monument, a no-take MPA in St. Croix, U.S.V.I. managed by the National Park Service. As developing standardized methods for acoustic telemetry is still a work in progress, the first half of this study focuses on determining appropriate tools for generating home range size estimates for great barracuda and analyzing ecological parameters driving these results. The second half of this study focused on the use of network analysis to look at spatial divisions within individual home ranges and to compare individual to population level spatial patterns, as well as to generate a relative estimate of population density within the park. Barracuda within the park demonstrated high site fidelity to individual territories, but at the population level they consistently used all habitats within the array. Core use areas within home ranges were evenly distributed throughout all habitats monitored by the acoustic array, although movement corridors were detected along high rugosity reef structures. Greater population densities within the park indicate that density dependent behaviors may be influencing habitat use within the park, and suggest that barracuda are contributing high levels of top down pressure through predation within the park boundaries.
8

Les rides de Barracuda et de Tiburon, à l'Est de la subduction des Petites Antilles : origine, évolution et conséquences géodynamiques

Pichot, Thibaud 18 June 2012 (has links) (PDF)
Les rides de Barracuda et de Tiburon sont deux reliefs sous-marins situés dans la partie ouest de l'océan Atlantique, là où la lithosphère océanique des plaques Amérique du Nord (NAM) et Amérique du Sud (SAM) est entraînée par subduction sous la plaque Caraïbe, formant l'arc volcanique des Petites Antilles et le prisme d'accrétion de Barbade. Le processus et la période de soulèvement conduisant au relief actuel de ces rides (qui semblent être un marqueur important dans l'histoire géodynamique de la région) sont sujets à débat depuis des décennies.L'interprétation de nouvelles données de sismique réflexion et de bathymétrie multifaisceaux acquises à travers les rides de Barracuda et de Tiburon (campagne Antiplac, 2007 ) a permis de dater les périodes de soulèvements des rides et réaliser des reconstructions paléogéographiques incluant les flux sédimentaires majeurs, depuis le Crétacé jusqu' à l'Actuel.L'analyse structurale révèle des phases de réactivations tardives d'anciennes zones de fractures dans un contexte transpressif, conduisant aux surrections des rides de Tiburon et de Barracuda.Les processus géologiques possibles impliqués dans la formation des rides de Barracuda et de Tiburon coïncident avec les modèles cinématiques récents décrivant les mouvements relatifs entre les plaques NAM et SAM, le long de la limite de plaque diffuse.Ces résultats permettent de mieux définir la limite de plaque entre NAM et SAM. Elle est nécessairement hétérogène exploitant les zones de faiblesses dans la lithosphère que sont les zones de fracture. Au sein de cette limite de plaque la lithosphère serait donc fragmentée.
9

A Quantitative Assessment of the January 2010 Cold Spell Effect on Mangrove Utilizing Coral Reef Fishes from Biscayne National Park, Florida

Ellis, Jeffrey M. 01 July 2015 (has links)
This study examined the effects of the January 2010 cold spell on mangrove utilizing coral reef fishes off the southeast coast of Florida, USA, in the vicinity of Biscayne National Park (BNP). An ongoing, fishery-independent mangrove visual survey documenting fish assemblages in BNP provided data from the years 1998 to 2014 for examination. Of particular interest were the presence, abundance, and size structure for five mangrove utilizing coral reef fishes: sergeant major (Abudefduf saxatilis), yellowfin mojarra (Gerres cinereus), schoolmaster snapper (Lutjanus apodus), gray snapper (Lutjanus griseus), and great barracuda (Sphyraena barracuda). These species were selected for analysis due to their economic and ecologic importance, their potential as environmental indicators, their connectedness to multiple habitats, and their abundance within the available data set. Data were collected using a modified visual ‘belt transect’ method, consisting of 60 m2 transects running parallel to the mangrove shorelines. Data for average length of fish were reconstructed to form standard normal distributions and the resulting lengths were assigned to various age-classes to create species-specific length-frequency distributions. Variations in presence and abundance were examined across three time periods (1998-2009; 2010-2011; 2012-2014), as well as comparisons of length-frequency distributions. Following the January 2010 cold spell, the presence and abundance values for the two years immediately following the event were significantly decreased compared to the years prior to the cold spell for most of the five species at either mainland (ML) or leeward key (LK) locations. Additionally, the presence and abundance estimates typically remained statistically decreased when compared against the remaining years in the available data set. The size structures for the majority of the five species at either location, however, were not consistently significantly different between the three time periods, as was hypothesized. Instead, the analyses showed mixed results, with the size structure typically shifting towards smaller individuals immediately following the event. These findings suggest that drops in water temperature resulting from cold spells are capable of directly impacting mangrove utilizing reef fish species, albeit to varying degrees depending on various factors, such as physiological tolerances, ecological life history strategies, and habitat requirements.
10

Distribution, Abundance and Movement of Fish among Seagrass and Mangrove Habitats in Biscayne Bay

Goebel, Patrick C 17 March 2016 (has links)
Inshore tropical and subtropical estuaries harbor a relatively high abundance and diversity of organisms. Specifically within estuaries, mangrove and seagrass habitats provide shelter and food for a plethora of organisms, through some or all their life histories. Given the biological connection between offshore coral reefs and coastal estuaries, there is a critical need to understand the underlying processes that determine distribution and abundance patterns within mangrove-seagrass habitats. The predatory fish assemblage within the mangrove and seagrass beds of Biscayne Bay, Florida (USA), was examined over 24-hr. time periods along a distance and habitat gradient from the mangrove edge and nearshore environment (0–300 m) to farshore (301–700 m) seagrass beds. This thesis also investigated the occurrence, distribution and timing of reef fish movement between offshore coral reef habitat and inshore seagrass beds over 24-hr periods. Results indicate that fish predators differed over both the sampling period and with distance from mangrove edge. The results also demonstrated reef fishes move into Biscayne Bay at dusk and exit at dawn by utilizing Broad Creek Channel as a passageway. This work supports the idea of diel migration of selected reef fishes to inshore seagrass beds and highlights the importance of connective channels between habitats. The results suggest that the degradation or loss of seagrass habitat could differentially impact the life-history stages of reef fish species.

Page generated in 0.0407 seconds