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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.
1

Automated Monitoring of River Ice Processes from Shore-based Imagery

Ansari, Saber January 2016 (has links)
Ice plays an important role in hydraulic processes of rivers in cold regions such as Canada. The formation, progression, recession and breakup of river ice cover known as river ice processes affect river hydraulics, sediment transport characteristics as well as river morphology. Ice jamming and break up are responsible of winter flash floods, river bed modification and bank scour. River ice cover monitoring using terrestrial images from cameras installed on the shores can help monitor and understand river ice processes. In this study, the benefits of terrestrial monitoring of river ice using a camera installed on the shore are evaluated. A time-lapse camera system was installed during three consecutive winters at two locations on the shores of the Lower Nelson River, in Northern Manitoba and programmed to take an image of the river ice cover approximatively every hour. An image analysis algorithm was then developed to automatically extract quantitative characteristics of the river ice cover from the captured images. The developed algorithm consists of four main steps: preprocessing, image registration, georectification and river ice detection. The contributions of this thesis include the development of a novel approach for performing georectification while accounting for a fluctuating water surface elevation, and the use of categorization approach and a locally adaptive image thresholding technique for target detection. The developed algorithm was able to detect and quantify important river ice cover characteristics such as the area covered by ice, border ice progression and ablation rate, and river ice break up processes with an acceptable accuracy.
2

Landbaserad lotsning : Möjligheter och begränsningar / Shorebased pilotage : Potentials and limitations

Green, Peter, Haglund, Emil January 2009 (has links)
<p>Efter ett förslag om förändring och modernisering av lotsverksamheten lades fram, där det föreslogs att landbaserad lotsning eventuellt införs i framtiden, beslutade vi att undersöka och jämföra åsikter från verksamma inom lotsväsendet.</p><p>Det finns risk att man förlorar viktiga delar av en väldigt stor kunskapsbank, om man inte tar tillvara på denna genom att beakta lotsarnas synvinklar, vid ett utvecklande och moderniserande av lotssystemet.</p><p>Syftet var att kartlägga och kategorisera vad det finns för möjligheter och begränsningar med dagens lotssystem i förhållande till landbaserad lotsning. Vi har gjort en kvalitativ, fenomenografisk undersökning, där vi använt oss av intervjuer med öppna frågeställningar.</p><p>Det visade sig att det var lätt att se begränsningar med ett införande av landbaserad lotsning, främst på grund av att lotsarna inte anser sig kunna utföra sitt arbete på ett tillfredställande sätt. Den ekonomiska vinsten rådde det delade meningar om, men majoriteten ansåg att besparingen skulle bli obefintlig.</p> / <p>After a proposal of a reformation of the Swedish pilot system was expressed, where it proposed that shore-based pilotage will be implemented in the future, we decided to investigate and compare opinions from involved persons. There is a risk of losing important parts of a very large knowledge-base, if the pilots’ opinions are not taken into consideration, in the event of development of the pilot system.</p><p>The purpose was to examine and categorize the possibilities and limitation with the pilot system of today in relation to shore-based pilotage.</p><p>We have performed a qualitative, phenomenografic research, where we have used interviews with open questions.</p><p>It was easy to find limitations if shore-based pilotage should be implemented, mostly because the pilots did not expect to be able to perform their work in a satisfactory way. The opinions regarding the economical profit differ, but the majority thought that the savings would be nonexistent.</p>
3

Landbaserad lotsning : Möjligheter och begränsningar / Shorebased pilotage : Potentials and limitations

Green, Peter, Haglund, Emil January 2009 (has links)
Efter ett förslag om förändring och modernisering av lotsverksamheten lades fram, där det föreslogs att landbaserad lotsning eventuellt införs i framtiden, beslutade vi att undersöka och jämföra åsikter från verksamma inom lotsväsendet. Det finns risk att man förlorar viktiga delar av en väldigt stor kunskapsbank, om man inte tar tillvara på denna genom att beakta lotsarnas synvinklar, vid ett utvecklande och moderniserande av lotssystemet. Syftet var att kartlägga och kategorisera vad det finns för möjligheter och begränsningar med dagens lotssystem i förhållande till landbaserad lotsning. Vi har gjort en kvalitativ, fenomenografisk undersökning, där vi använt oss av intervjuer med öppna frågeställningar. Det visade sig att det var lätt att se begränsningar med ett införande av landbaserad lotsning, främst på grund av att lotsarna inte anser sig kunna utföra sitt arbete på ett tillfredställande sätt. Den ekonomiska vinsten rådde det delade meningar om, men majoriteten ansåg att besparingen skulle bli obefintlig. / After a proposal of a reformation of the Swedish pilot system was expressed, where it proposed that shore-based pilotage will be implemented in the future, we decided to investigate and compare opinions from involved persons. There is a risk of losing important parts of a very large knowledge-base, if the pilots’ opinions are not taken into consideration, in the event of development of the pilot system. The purpose was to examine and categorize the possibilities and limitation with the pilot system of today in relation to shore-based pilotage. We have performed a qualitative, phenomenografic research, where we have used interviews with open questions. It was easy to find limitations if shore-based pilotage should be implemented, mostly because the pilots did not expect to be able to perform their work in a satisfactory way. The opinions regarding the economical profit differ, but the majority thought that the savings would be nonexistent.
4

Western Gray Whale (Eschrichtius robustus) Mother and Calf Ecology Off Sakhalin Island

Sychenko, Olga Aleksandrovna 2011 May 1900 (has links)
The western population of gray whales (Eschrichtius robustus) is endangered with approximately 130 individuals remaining. Many individuals return annually to the same feeding sites off northeastern Sakhalin Island, indicating a site-specific dependence to this geographic area. This apparently critically important habitat is especially vital for nursing females and their calves, as female energetic requirements are increased during lactation, and calves need to be ready to separate and begin to feed on their own. This study focuses on movements, respirations and behavioral patterns of mother/calf pairs on their feeding ground, with data collected during summer-autumn of 2002-2009. Shore-based observations included three methods: theodolite tracking, focal-animal behavior sampling, and photo-identification. Whales were categorized as three groups of individuals: mother/calf pairs, weaned calves, and other individuals. Analyses were performed to assess differences between groups of individuals, and in relation to their behavior. The null hypothesis of the study was that there were no differences in movement/respiration/behavioral patterns and habitat use between different groups of individuals. Results did not support this hypothesis. Significant differences in movements and respirations were found for certain groups of individuals. These differences also varied in relation to the whales' behavioral activity (feeding, feeding/traveling, and traveling). The shore-based photography was used to obtain additional information on individuals (especially mother/calf pairs) and their sightings, as well as to evaluate the success of this approach. A total of 144 individuals, including 10 females (sighted with calves) and 31 calves were identified during 2004-2009. The shore-based photo-identification approach was successful, and due to being a non-invasive technique, is recommended as a supplemental approach to vessel-based photo-ID efforts. Reproductive success and survival of western gray whales are concern especially due to the presence of industrial activity in the area, as well as recently increased mortalities of female gray whales off Japan. Therefore, the results of this study indicate the importance of considering differences in needs and habitat utilization of different groups of individuals for basic science information as well as for management purposes of protection of western gray whales.
5

Smittspridning ombord på fartyg : En studie om hantering av smittspridning ombord på fartyg och rederiers smittskyddsplaner / The spread of infection onboard ships : A study on managing the spread of infection on board ships and shipping companies' infection control plans

Djurberg, Fabian, Danielsson, Mak January 2024 (has links)
År 2020 drabbades världen av Covid-19. Spridningen av viruset resulterade i att många länder upprättade en lockdown. Detta påverkade sjöfartsbranschen negativt och ställde till med problem när folk blev sjuka. Detta är på grund av den unika miljön som finns ombord på fartyg. Syftet med studien var att analysera och utvärdera hur olika fartyg och rederier agerade under covid-19-pandemin med fokus på effektivitet, framgång och problem när det kommer till smittskydd. Studiens frågeställningar berörde hur rederiers existerande smittskyddsplaner såg ut och huruvida de kan förbättras, vilka lärdomar som kan dras om smittspridning ombord på fartyg och huruvida en förbättrad smittskyddsplan kan konstrueras utifrån de som redan existerar. En kvalitativ metod i form av granskning och inläsning av studier i området smittspridning i allmänhet samt studier om utbrott av covid-19 ombord på fartyg. Smittskyddsplaner samlades in genom ett mailutskick till svenska rederier. Resultatet visar att rederierna efterlevde många av WHO:s riktlinjer där de även implementerade egna tillägg till den ombordhavna smittskyddsplanen. Vi kom även fram till att landbaserad assistans är en viktig komponent för att kunna bekämpa smittspridning ombord. / In 2020, the world was struck by Covid-19. The spread of the virus resulted with many countries establishing  lockdowns. This negatively affected the shipping industry and caused problems when people got sick. This is because of the unique environment that exists on board ships. The purpose of the study was to analyze and evaluate how different ships and shipping companies acted during the COVID-19 pandemic with a focus on efficiency, success and problems when it came to controlling the spread of infections. The study's questions concerned how shipping companies' infection control plans were complied with and whether they can be improved, what lessons can be learned about the spread of infections on board ships and whether an improved infection control plan can be constructed from those that already exist. A qualitative method of reviewing and reading studies in the field of infection control in general and studies on COVID-19 outbreaks on board ships. Infection control plans were collected through a mailing to Swedish shipping companies. The results showed that the shipping companies complied with many of the WHO's guidelines where they also implemented their own additions to the on-board infection control plan. We also came to the conclusion that land-based assistance is an important component for combating the spread of infections on board.

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