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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

The maximum time interval of time-lapse photography for monitoring construction operations

Choi, Ji Won 01 November 2005 (has links)
Many construction companies today utilize webcams on their jobsites to monitor and record construction operations. Jobsite monitoring is often limited to outdoor construction operations due to lack of mobility of wired webcams. A wireless webcam may help monitor indoor construction operations with enhanced mobility. The transfer time of sending a photograph from the wireless webcam, however, is slower than that of a wired webcam. It is expected that professionals may have to analyze indoor construction operations with longer interval time-lapse photographs if they want to use a wireless webcam. This research aimed to determine the maximum time interval for time-lapse photos that enables professionals to interpret construction operations and productivity. In order to accomplish the research goal, brickwork of five different construction sites was videotaped. Various interval time-lapse photographs were generated from each video. Worker?s activity in these photographs was examined and graded. The grades in one-second interval photographs were compared with the grades of the same in longer time interval photographs. Error rates in observing longer time-lapse photographs were then obtained and analyzed to find the maximum time interval of time-lapse photography for monitoring construction operations. Research has discovered that the observation error rate increased rapidly until the 60-second interval and its increasing ratio remained constant. This finding can be used to predict a reasonable amount of error rate when observing time-lapse photographs less than 60-second interval. The observation error rate with longer than 60-second interval did not show a constant trend. Thus, the 60-second interval could be considered as the maximum time interval for professionals to interpret construction operations and productivity.
2

High-Temporal Resolution Photography for Observing Riparian Area Use and Grazing Behavior

Nichols, M.H., Ruyle, G.B., Dille, P. 07 1900 (has links)
Observation is a simple method of acquiring information and is a critical step in the scientific method for both developing and investigating testable hypotheses. Cameras have long played a role in observation, and as technology advances, new tools and methods for collecting, interrogating, and displaying large quantities of high-resolution images have evolved. We describe an automated digital time-lapse camera system and present an example field deployment to observe the temporal and spatial patterns of riparian use by humans and animals during a 3-mo period. We also describe software tools for image interrogation and visualization, as well as new information gathered through their use. The system was tested in 2014, in a 2.4-ha site within the ApacheSitgreaves National Forest in east central Arizona, United States where elk (Cervus elaphus nelsoni) and cattle grazed. Photographs were taken every 30 sec for 38 d, after which an electric fence was installed to restrict cattle access and the time step was increased to every 3 min. We observed that elk exhibited the unique behavior of standing in and traveling within the stream channel while grazing and tended to graze and lie in close proximity to the channel. Cattle drank from, but typically did not enter, the stream channel and tended to lie away from the channel. Recreational use by people had the distinct impact of dispersing elk from the riparian corridor. Zoomable time-lapse videos allowed us to observe that in contrast to the cattle, elk grazed while lying down. High-temporal resolution photography is a practical tool for observing phenomena that are important for local resource management. Published by Elsevier Inc. on behalf of The Society for Range Management.
3

Aerial photography and environmental impact analysis : the potential contribution of comparative interpretation of multi-temporal aerial photographs to Environmental Impact Analysis

Bayne, Sandra Maureen January 1984 (has links)
Bibliography: pages 123-133. / The hypothesis was advanced that comparative interpretation of multi-temporal aerial photographs can be used as a tool in Environmental Impact Analysis (EIA). To test this hypothesis a site, Silwerstroomstrand, approximately 40 kilometres north of Cape Town on the West coast was chosen. An analysis of the site was carried out using aerial photographs taken in 1938, 1960, 1968, 1971, 1977, 1981 and 1983 at scales ranging from 1:7 000 to 1:50 000. Development of the site for recreation began in 1972 and in 1976 for water extraction. Pre-development photographs, 1938, 1960, 1968 and 1971, were stereoscopically compared and the observations were interpreted using a systems approach. From the analysis of the photographs and information on past landuse, the dynamics of the site were described with particular attention to the response of that environment to perturbations such as fire and removal of vegetation. Development actions were analysed to establish any similarity to past perturbations and on the basis of similarities, predictions of probable future responses of the site (and hence impacts) were made. The predicted impacts were compared with: 1. the interpretation of post-development photographs. 2. Impacts identified by a multi-disciplinary panel after a visit to the site. It was found that the major limitation of multi-temporal aerial photographs was the spatial resolution of the early (pre 1970) photographs. However, the capabilities of the tool for quantitative and semi-quantitative data gathering; promoting an understanding of spatial and temporal relationships; monitoring change; communicating information and the fact that it is economical means that it has a positive contribution to make to Environmental Impact Analysis is suggested that the optimal use of the tool of comparative interpretation of multi-temporal aerial photography is to combine it with other tools such as site visits and multi-disciplinary panels.
4

Automatizovaný posun pro pořizování časosběrných snímků / Automated device for shift time-lapse capture

Trenz, Tomáš January 2018 (has links)
Automatic slider for time lapse photography and the creation of a functional sample is described in this diploma work. The individual components and the control program itself are analyzed.
5

Evaluating the use of photography for monitoring feeding habits of common murre (Uria aalge)

Rydevik, Elin January 2021 (has links)
Seabirds are often used as indicator species for changes in marine ecosystems due to the species visibility and sensitivity to changing conditions, such as changes in prey abundance. They often reside in habitats affected by anthropogenic impacts such as large-scale fisheries and pollution. Understanding the connection between seabirds and their surrounding environment can give us important insight about the ecology of the ocean and how anthropogenic pressures affects it. Studying feeding habits, and foraging behavior especially, is useful for understanding seabird´s responses to changing environments. Feeding studies are commonly used in seabird monitoring and requires a lot of time and resources. Monitoring of seabirds are also logistically challenging, and the risk of disturbing bird colonies must be considered. It can be especially complicated when studying cliff nesting seabirds such as the common murre, Uria aalge, the study species for this thesis. Photography as a method for monitoring seabirds may limit the need of people on site, hence minimize disturbance and save time and resources. This study provides insight in whether it is a viable option to use photography instead of on-site field studies when monitoring sea birds. This was accomplished by installing cameras and monitor a feeding study at Stora Karlsö, Sweden, parallel with performing the usual monitoring in the field. This thesis makes it clear that a camera study very well could replace the field study without any larger concerns, although, improvements need to be considered if the study is to maintain a high quality and for results to be reliable.
6

"Seeing is believing" : A visual communication approach to Climate Change, through the Extreme Ice Survey

Matthews, Jamie January 2015 (has links)
Communication plays a fundamental role in shaping our understanding of complex issues such as climate change. Too often scientists and journalists complain that the public does not fully comprehend climate change as they cannot see it. Adhering to calls for a need to propel away from media representations of climate change to a focus on more case-specific research, this Master Thesis analyses the aspect of visualisation within climate change communication with a focus on a contemporary example, the Extreme Ice Survey (EIS), as a case-specific study. EIS give a visual voice to our planets changing eco-systems, where an emphasis is placed on visually documenting the adverse effects climate change has on the planets glaciers, through conventional photography and time-lapse photography. Adhering to the need for further studies of visual representations towards the environment this thesis deploys an image analysis to investigate how meaning is framed through the EIS’s photographs and time-lapse videos. A collective reading between the photographs and their accompanying written captions highlighted contradictive frames of beauty and uncertainty. Additionally, as climate change is predominately seen as an abstract entity, a metaphor analysis was also applied to open further frames of thought into more comprehensible understandings. Integrating both still images and moving images into the study provided different results. Time-lapse videos were analysed to open up new developments of seeing and to extract potential frames of unfolding narratives, perspective and time.
7

Genesis, conservation and deformation of ice-rich mountain permafrost:

Kenner, Robert 30 May 2018 (has links) (PDF)
This thesis analyses ice-rich mountain permafrost with regard to its genesis, distribution, deformation and interaction with other environmental factors. The processes influencing ground ice formation in ice-rich and ice-poor mountain permafrost are highlighted. Factors influencing the presence of ice-rich permafrost are identified and their individual or combined effect on frozen ground is determined. Based on these findings, a new permafrost distribution map of Switzerland was created, which specifies permafrost temperature and ice contents and considers rock glacier creep paths. The deformation of rock glaciers is investigated with newly developed monitoring systems and concepts. This enables a better understanding of the processes leading to rock glacier acceleration at different time scales.
8

Genesis, conservation and deformation of ice-rich mountain permafrost:: Driving factors, mapping and geodetic monitoring

Kenner, Robert 29 January 2018 (has links)
This thesis analyses ice-rich mountain permafrost with regard to its genesis, distribution, deformation and interaction with other environmental factors. The processes influencing ground ice formation in ice-rich and ice-poor mountain permafrost are highlighted. Factors influencing the presence of ice-rich permafrost are identified and their individual or combined effect on frozen ground is determined. Based on these findings, a new permafrost distribution map of Switzerland was created, which specifies permafrost temperature and ice contents and considers rock glacier creep paths. The deformation of rock glaciers is investigated with newly developed monitoring systems and concepts. This enables a better understanding of the processes leading to rock glacier acceleration at different time scales.

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