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Full-Text Articles in Physical Sciences and Mathematics
Global Digital Elevation Model Accuracy Assessment In The Himalaya, Nepal, Luke G. Miles
Global Digital Elevation Model Accuracy Assessment In The Himalaya, Nepal, Luke G. Miles
Masters Theses & Specialist Projects
Digital Elevation Models (DEMs) are digital representations of surface topography or terrain. Collection of DEM data can be done directly through surveying and taking ground control point (GCP) data in the field or indirectly with remote sensing using a variety of techniques. The accuracies of DEM data can be problematic, especially in rugged terrain or when differing data acquisition techniques are combined. For the present study, ground data were taken in various protected areas in the mountainous regions of Nepal. Elevation, slope, and aspect were measured at nearly 2000 locations. These ground data were imported into a Geographic Information System …
Automated Extraction Of Community Mobility Measures From Gps Stream Data Using Temporal Dbscan, Sungsoon Hwang, Timothy Hanke, Christian Evans
Automated Extraction Of Community Mobility Measures From Gps Stream Data Using Temporal Dbscan, Sungsoon Hwang, Timothy Hanke, Christian Evans
Sungsoon Hwang
Inferring community mobility of patients from GPS data has received much attention in health research. Developing robust mobility (or physical activity) monitoring systems relies on the automated algorithm that classifies GPS track points into events (such as stops where activities are conducted, and routes taken) accurately. This paper describes the method that automatically extracts community mobility measures from GPS track data. The method uses temporal DBSCAN in classifying track points, and temporal filtering in removing noises (any misclassified track points). The result shows that the proposed method classifies track points with 88% accuracy. The percent of misclassified track points decreased …
Identifying Ditch Geometry And Top Of The Bank Location Using Airborne Lidar Point Cloud, Naime Celik
Identifying Ditch Geometry And Top Of The Bank Location Using Airborne Lidar Point Cloud, Naime Celik
Open Access Theses
The geometry of agricultural drainage ditches is very important in crop production as it impacts drainage of cropland and affects vegetation and soil erosion along the banks of the ditches. Thus, implementation of water conservation and management practices in engineered and natural ditches necessitates determination of ditch geometry along the reach of the ditch. This study explores the use of airborne commercial Light Detection and Ranging (LiDAR) technology to identify the top of the ditch banks. The method was developed to obtain the normalized cross sectional shape of the ditch using one-dimensional spline fits to ground classified points from the …
Compression Of Gps Trajectory Data : Benchmarking Framework And New Approach, Jonathan Muckell
Compression Of Gps Trajectory Data : Benchmarking Framework And New Approach, Jonathan Muckell
Legacy Theses & Dissertations (2009 - 2024)
GPS-equipped mobile devices such as smart phones and in-car navigation units are collecting enormous amounts of spatial and temporal information that traces a moving object's path. The exponential increase in the amount of such trajectory data has caused three major problems. First, transmission of large amounts of data is expensive and time-consuming. Second, queries on large amounts of trajectory data require computationally expensive operations to extract useful patterns and information. Third, GPS trajectories often contain large amounts of redundant data that waste storage and cause increased disk I/O time. These issues can be addressed by algorithms that reduce the size …